Estimating canopy cover from color digital camera image of rice field

Canopy cover (CC) is a good predictor variable for plant growth parameters such as leaf area index and aboveground biomass. A nondestructive, low-cost, and convenient method is presented for estimating CC using digital camera image analysis. CC was estimated by the ratio of plant pixels to total pixels of digital camera image of rice field. To determine the criteria for segmenting the rice plant from variable soil background, three mosaic images for rice plant, flooded/bare soil, and algae-infested background were prepared from digital camera images that were taken in various field conditions. An image analysis program was developed in Visual Basic to extract red, green, and blue (RGB) features from the mosaic images, calculate RGB-based color indices, and compute the minimum segmentation error for separating rice plant from background. When judged by the segmentation error, modified excessive green index (MEGI) showed the highest potential for segmenting rice plant from flooded/bare soil background, followed by normalized green (g) and excessive green index (EGI). At the threshold MEGI value of 0.03, the segmentation error was the lowest as 0.13%. Any single index considered was not satisfactory in segmenting rice plant from algae-infested background. However, a discriminant function of 1.2553EGI + 0.01735G − 0.01474B was successful in segmenting rice plant from flooded/bare soil and algaeinfested background with segmentation errors of 0.34 and 1.17%, respectively. CC for four rice varieties from tillering to booting stage was estimated based on the threshold value of MEGI and discriminant function and also manually using commercial software. Both estimates of CC showed good relationship of r² = 0.94, suggesting that a digital camera could be used efficiently for measuring the CC of rice field.     

Viewpoints on synergising ASEAN academic visibilities through research collaboration and the establishment of an ASEAN Citation Index Database1

This opinion article expresses two key viewpoints regarding the options for Association of South‐East Asian Nations (ASEAN) universities in pursuit of fulfilling the demand for greater research visibility and academic reputation. The first viewpoint outlines the importance of promoting research collaboration among ASEAN researchers and their international peers in increasing the visibility and impact of ASEAN research. The second viewpoint examines the ASEAN research characteristics, the challenges and existing best practices of its journal publishing landscape, the potential role of non‐ASEAN international journals in improving the profile of ASEAN research and explores the needs and benefits of establishing an ASEAN Integrated Journal Publishing Network (IJPN). It is through these combined approaches, we believe, that effective policy change, the standardisation of publishing structure, procedures, and systems to drive journal development, improvement of journal quality, and establishment of a consistent framework for measuring researcher performance will result. This article also includes a proposal for the IJPN structure and implementation plan, and highlights the key benefits of taking a collaborative approach to achieving this common goal.     

Distribution and migration of Japanese common squid, Todarodes pacificus, in the southwestern part of the East (Japan) Sea

Data on squid catches of Korean and Japan, water temperatures at depth of 100 m, and night-visible images of fishing boats collected in the East (Japan) Sea from 1970 to 1999 were analyzed to examine the distribution and migration of the Japanese common squid, Todarodes pacificus, in the southwestern part of the East (Japan) Sea. The main fishing grounds detected from squid catch in each grid (0.5° latitude × 0.5° longitude) by Korean squid fishery and night-visible images provided by the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) were situated in the southwestern part of the East (Japan) Sea. The distribution and migration route was illustrated from squid catch in each grid and DMSP OLS image. In years of high catches, the fishing grounds were situated mainly between Ulleung Island and the eastern coastal waters of Korea, while in years of low catches they were situated between Ulleung Island and the Yamato Bank in the central East (Japan) Sea. The center of fishing activity began moving northward from around the Korea/Tsushima strait to the northern boundary of the Tsushima Warm Current in March, reaching into the Yamato Bank in September, and then returning to the strait by February. The northward and southward migration routes differed; the northward migration route occurred closer to the mainland coast of Korea than the southward migration route did. This work suggests T. pacificus begin their northward migration almost 2 months earlier than previously suggested.     

Electrokinetic remediation of heavy metal-contaminated soils: performance comparison between one- and two-dimensional electrode configurations

Journal of Soils and Sediments - Electrokinetic (EK) soil remediation is significantly affected by the electrode configurations. Therefore, this study was conducted to compare the performance of...     

Estimation of productivity growth,technical progress,and efficiency changes in the Korean offshore fisheries

In this study, changes in total factor productivity of 12 Korean offshore fisheries between 1997 and 2009 were estimated through the Malmquist productivity index, which is a nonparametric method. Also, the cause of such changes in productivity of each fishery was analyzed more specifically by segmenting into factors for technological progress and technical efficiency. As a result of this analysis, the total factor productivity change of the entire offshore fisheries was −6.0 %. Changes in the technical efficiency and technological level factors, respectively, contributed 0.2 and −6.2 % to this rate of decrease in total factor productivity; that is, inactivity of technological progress led to the decrease in productivity of the offshore fisheries. In addition, technological progress and technical efficiency were found to differently influence the change in total factor productivity of each fishery. In order for each fishery to improve productivity, better rational fisheries management policies by the government and efforts by the fishing industry and individual fishing business units must accompany factors that promote productivity increase.     

DEMAND FOR AQUACULTURE PRODUCTS IN TAIWAN: AN APPLICATION OF THE GENERALIZED MODEL

ABSTRACT

Policy decisions on what aquaculture products to develop require information on consumer demand for cultured species. However, information on the structure of demand for aquaculture products is limited and what few studies there are in Taiwan, where aquaculture is a major industry, suffer from methodological problems. To clear up some of these problems, we used modified nonnested testing techniques and performance forecasting to determine which generalized models could best estimate the demand for Taiwanese aquaculture products. The results of modified nonnested testing of the aquaculture demand system showed that prices predetermined and quantities predetermined could be used to estimate demand. The generalized ordinary demand model was able to better forecast performance than the generalized inverse demand model. We used the likelihood ratio test to discriminate among the four competing models for the generalized ordinary model; the AIDS model could be more suitably applied to the data. A more general model that is able to incorporate different dynamic structures (partial adjustment, first autoregressive, and static). This general framework is applied to the AIDS model. The first autoregressive AIDS model we used to calculate the own and cross-price elasticities for milkfish, tilapia, shrimp, shellfish, and carps found that price elasticities varied across fish type, that some products had high long-run own price elasticities, and that the demand for aquaculture products was largely determined by inertia.     

Nanominerals, mineral nanoparticles, and Earth systems

Minerals are more complex than previously thought because of the discovery that their chemical properties vary as a function of particle size when smaller, in at least one dimension, than a few nanometers, to perhaps as much as several tens of nanometers. These variations are most likely due, at least in part, to differences in surface and near-surface atomic structure, as well as crystal shape and surface topography as a function of size in this smallest of size regimes. It has now been established that these variations may make a difference in important geochemical and biogeochemical reactions and kinetics. This recognition is broadening and enriching our view of how minerals influence the hydrosphere, pedosphere, biosphere, and atmosphere.     

Genetic variant BDNF (Val66Met) polymorphism alters anxiety-related behavior

A common single-nucleotide polymorphism in the brain-derived neurotrophic factor (BDNF) gene, a methionine (Met) substitution for valine (Val) at codon 66 (Val66Met), is associated with alterations in brain anatomy and memory, but its relevance to clinical disorders is unclear. We generated a variant BDNF mouse (BDNF(Met/Met)) that reproduces the phenotypic hallmarks in humans with the variant allele. BDNF(Met) was expressed in brain at normal levels, but its secretion from neurons was defective. When placed in stressful settings, BDNF(Met/Met) mice exhibited increased anxiety-related behaviors that were not normalized by the antidepressant, fluoxetine. A variant BDNF may thus play a key role in genetic predispositions to anxiety and depressive disorders.     

Effects of biochar on Cd and Pb mobility and microbial community composition in a calcareous soil planted with tobacco

An experiment was conducted with tobacco (Nicotiana tabacum L.) grown in a Cd- and Pb-contaminated calcareous soil amended with 0.0, 1.0, 2.5, and 5.0% (w/w) tobacco stalk biochar (BC). The BC amendment significantly increased organic matter, total C, N, P, and K contents of soil, and the C/N ratio. Bioavailable metal concentrations (DTPA extraction) decreased by increasing BC application rate. The 5.0% BC amendment significantly decreased the DTPA-extractable Cd and Pb by 10.4 and 13.6%, respectively. Correspondingly, the bioaccumulation and translocation factors of Cd and Pb also decreased by increasing the BC addition rates and this indicated that BC inhibited the uptake and transfer of both Cd and Pb by tobacco plants. Moreover, high-throughput sequencing revealed that BC increased Chao1 richness, Shannon’s diversity and Simpson’s diversity of bacterial communities of soil. The relative abundance and genera composition of Adhaeribacter, Rhodoplanes, Pseudoxanthomonas, and Candidatus Xiphinematobacter increased under BC treatments, while those of Kaistobacter, Lacibacter, and Pirellula decreased. Overall, BC increased soil nutrients (C, N, P, and K contents), enhanced bacterial diversity indexes and richness, and changed the bacterial community composition, which may all have contributed to reduce the mobility and bioavailability of both Cd and Pb in a calcareous soil.     

Evaluation of brief dietary questions to estimate vegetable and fruit consumption - using serum carotenoids and red-cell folate

OBJECTIVE: To evaluate responses to self-administered brief questions regarding consumption of vegetables and fruit by comparison with blood levels of serum carotenoids and red-cell folate. DESIGN: A cross-sectional study in which participants reported their usual intake of fruit and vegetables in servings per day, and serum levels of five carotenoids (alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin and lycopene) and red-cell folate were measured. Serum carotenoid levels were determined by high-performance liquid chromatography, and red-cell folate by an automated immunoassay system. SETTINGS AND SUBJECTS: Between October and December 2000, a sample of 1598 adults aged 25 years and over, from six randomly selected urban centres in Queensland, Australia, were examined as part of a national study conducted to determine the prevalence of diabetes and associated cardiovascular risk factors. RESULTS: Statistically significant (P<0.01) associations with vegetable and fruit intake (categorised into groups: /=4 servings per day) were observed for alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein/zeaxanthin and red-cell folate. The mean level of these carotenoids and of red-cell folate increased with increasing frequency of reported servings of vegetables and fruit, both before and after adjusting for potential confounding factors. A significant association with lycopene was observed only for vegetable intake before adjusting for confounders. CONCLUSIONS: These data indicate that brief questions may be a simple and valuable tool for monitoring vegetable and fruit intake in this population.