Chemical defense of a rare mint plant

Summary Analyses of leaf extracts ofDicerandra frutescens, a highly aromatic mint plant from central Florida listed as an endangered species, revealed presence of 12 closely related monoterpenes. The principal of these, (+)—trans-pulegol, is a new natural product, the synthesis of which is described. The terpenes are produced in glandular capsules that release their contents upon injury of the leaf. Data from bioassays with ants and cockroaches indicate that the terpenes serve for defense against insects.Dicerandra does, however, have a leaf-eating enemy, the caterpillar of a pyralid moth,Pyrausta panopealis. The discovery of a new natural product from an endangered species raises questions about the chemical implications of species extinction.     

Weight and chemical composition of some important oceanic zooplankton in the North Pacific Ocean

Wet and dry weight, total carbon, nitrogen, hydrogen, and ash contents were determined on 33 species of zooplankton distributed predominantly in the open sea region of the North Pacific. Sampling covered the waters from 44°N to the equator. Average percentage of dry weight to wet weight was about 19% of all samples from the whole area. Percentage dry weight of carbon in copepods was on an average 51.5%. The highest value, 66.6%, was obtained in eggs of the copepod Pareuchaeta sarsi. Mixed zooplankton was assumed to contain carbon comprising about 35 to 45% of the dry weight. Carbon contained in the zooplankton biomass existing in the upper 200 m in the western parts of the northern North Pacific and Bering Sea during spring and summer was estimated to range from 20 to 85 mg C/m³. Nitrogen content varied considerably with localities. Average ratio of carbon to nitrogen was 8.5 in subarctic copepods, and 4.1 in subtropic-tropic copepods. This ratio also varied with season. In the copepod Calanus cristatus the ratio was highest (10.0) in May, immediately after the spring bloom of phytoplankton, when the animals contained much fat. The ratio fell to 5.1 in December. There seemed to be a large seasonal variation in boreal zooplankton due to great fluctuations of environmental conditions, especially the amount of food available; in tropical species the range was small because of environmental uniformity. Average hydrogen content was about 6 to 10%. The percentage of ash to dry weight amounted to 39.3% in pteropods and 3.4% in copepods.     

Observations of dugong reproductive behavior in Trang Province,Thailand: further evidence of intraspecific variation in dugong behavior

The seagrass beds at Muk Island and Talibong Island in Thailand are important areas for dugong (Dugong dugon) feeding and reproduction. We used opportunistic observations during aerial surveys to investigate dugong mating behavior in shallow water areas near Talibong Island on three different days. The mating pattern was categorized by five stages: (1) following: the male followed the female, (2) approaching and stimulating: the male approached and muzzled the female, (3) pairing: both male and female swam in parallel, ventral to ventral or dorsal to dorsal side, (4) mounting: the male copulated with the female, and (5) separating: the male and female swam in different directions. Parental care of calves included one observation of a cow embracing her neonatal calf by the flippers.     

Fate estimation of estrogenic substances in an urban river by flux calculation.

This study investigated the fate of estrogenic substances in an urban river receiving discharge from wastewater treatment plants (WTPs) by flux calculation, focusing on the middle reaches of the Tama River in Tokyo, which is one of the most urbanized rivers in Japan. The level of estrogenic activity flux was almost negligibly small at the upstream station. The level was considerably raised after inflows from the WTPs and then the level declined in the lower reaches of the river. When contributions of estrogenic substances to estrogenic activity were estimated, estrone (E1) was the primary contributor to the total estrogenic activity in all the sampling stations, followed by estradiol (E2). The contribution of nonylphenol to estrogenic activity was small. The E1 and E2 accounted for approximately 90% or more of estrogenic activity in the Tama River. As for the total fluxes of the estrogenic substances in the study area in the Tama River, the proportion of flux associated with WTP discharge was approximately 100% of the total fluxes, and the effects of the tributaries flowing into the river were almost negligible. When the reduction ratios of estrogenic activity were calculated by the flux, the ratios were found to increase toward the lower reaches of the river. Similar changes were observed for E1. Meanwhile, the change of reduction ratios for E2 was different from that observed for estrogenic activity.     

Lead immobilization in mechanochemical fly ash recycling

In previous studies, we focused on a mechanochemical process for recycling fly ash for use in cement; this process was expected to immobilize heavy metals in the fly ash, a desirable outcome in light of the fact that recycled fly ash is commonly used in the synthesis of inorganic materials. Here, we investigated the leaching of lead (Pb) from fly ash treated by a mechanochemical process and from cement prepared from the treated fly ash. We used lead oxide (PbO), a typical Pb compound in fly ash, as a model substance. Mechanochemical treatment of the fly ash inhibited Pb leaching by 93%, and further inhibition (more than 99.9%) was observed in cement produced from the treated fly ash. During the mechanochemical treatment, PbO was reduced to Pb by iron from the stainless-steel mill used for processing, and the lower solubility of Pb in water resulted in immobilization of the Pb.     

Anisotropy of environmental perception caused by spatial changes during locomotion

Daily perception entails an immediate awareness of the environment surrounding the body. To explore its dynamic nature during locomotion, this study tests the hypothesis that significant changes in spatial volume induce the directional focusing (i.e., anisotropy) of environmental perception. To capture perceptual activity in its natural state, we have attempted an approach using the feeling of visual pressure (i.e., felt presence) caused by the surrounding environment. In the present experiment that uses a virtual reality setup, participants were required to continuously rate their feelings while moving along a virtual outdoor route. Their ratings were analyzed in relation to environmental measurements along the route, such as the visible area of buildings and the horizontal extent of surrounding space. The relationship between the ratings and measurements was explored by using two prediction models: with and without consideration of perceptual anisotropy. The results suggested that a consideration of anisotropy improved the prediction accuracy, thereby supporting our hypothesis.     

Development of an educational model for sustainability science: challenges in the Mind–Skills–Knowledge education at Ibaraki University

Modern society confronts multiple sustainability challenges, including population growth, resources limitations, and a deteriorating environment. As a response, sustainability science education plays a major role in developing human capacity to manage these issues. This paper proposes the concept of “sustainability science education across Mind–Skills–Knowledge” as well as the competencies to be acquired and its pedagogy. This paper evaluates the effectiveness of such an educational system and its method of implementation using the example of the Graduate Program on Sustainability Science (GPSS), which was started at Ibaraki University in 2009.     

Comparison of air pollutant emissions among mega-cities

Ambient measurements of hydrocarbons, carbon monoxide and nitrogen oxides from three mega-cities (Beijing, Mexico City, Tokyo) are compared with similar measurements from US cities in the mid-1980s and the early 2000s. The common hydrocarbon pattern seen in all data sets suggests that emissions associated with gasoline-fueled vehicles dominate in all of these cities. This commonality suggests that it will be efficient and, ultimately, cost effective to proceed with vehicular emission controls in most emerging mega-cities, while proceeding with development of more locally appropriate air quality control strategies through emissions inventory development and ambient air monitoring. Over the three decades covered by the US data sets, the hydrocarbon emissions decreased by a significant factor (something like an order of magnitude), which is greater than suggested by emission inventories, particularly the EDGAR international inventory. The ambient hydrocarbon and CO concentrations reported for the three non-US mega-cities are higher than present US ambient concentrations, but lower than those observed in the 1980s in the US. The one exception to the preceding statement is the high concentrations of CO observed in Beijing, which apparently have a large regional contribution.     

Evaluation of uncertainties originating from the different modeling approaches applied to analyze regional groundwater flow in the Tono area of Japan

Qualitative evaluation of the effects of uncertainties originating from scenario development, modeling approaches, and parameter values is an important subject in the area of safety assessment for high-level nuclear waste disposal sites. In this study, regional-scale groundwater flow analyses for the Tono area, Japan were conducted using three continuous models designed to handle heterogeneous porous media. We evaluated the simulation results to quantitatively analyze uncertainties originating from modeling approaches. We found that porous media heterogeneity is the main factor which causes uncertainties. We also found that uncertainties originating from modeling approaches greatly depend on the types of hydrological structures and heterogeneity of hydraulic conductivity values in the domain assigned by modelers. Uncertainties originating from modeling approaches decrease as the amount of labor and time spent increase, and iterations between investigation and analyses increases.     

Geographic mosaic of mutually exclusive dominance of obligate commensals in symbiotic communities associated with a burrowing echiuran worm

Species richness and community composition of symbionts associated with the burrowing echiuran worm, Ochetostoma erythrogrammon Leuckart & Rüppell, 1828, were quantitatively surveyed on subtropical intertidal flats in the Ryukyu Archipelago, Japan. Overall, we recorded seven species of burrow associates, including at least six obligate commensals. According to symbiont community composition, the study sites were largely divided into two groups; one was characterized by the dominance of a snapping shrimp, Alpheus barbatus Coutière, 1897, and the other by the dominance of a scale worm, Lepidonotus sp. Furthermore, a granulometric analysis showed that the sediment characteristics differed significantly between shrimp- and scale worm-dominant sites in terms of median diameter and inclusive graphic standard deviation. These results suggest that these symbionts have different habitat requirements, resulting in the mutually exclusive dominance pattern. Our findings indicate that habitat heterogeneity is important to the evaluation and conservation of the symbiotic diversity in intertidal flats.