Optimization of the purification method for dioxin analysis in human serum and temporal changes in background dioxin levels in the general population

To perform high quality and high throughput measurements, complicated purification procedure by two rounds of open column chromatography was simplified by appraising the components and adding a sufficient amount of adsorbents to the column. The procedure consists of two open column techniques using a multi-layer silica gel column and an active carbon dispersed silica gel column. This purification procedure is used in "Standard manual for dioxin analysis in human blood" published in 2000 (Ministry of Health and Welfare, Japan, 2000). Consequently, a purification procedure using only 1 g of 10% AgNO(3)/silica gel can remove the matrix of blood serum as effectively as a multi-layer silica gel column. In addition, 0.1 g of carbon silica gel, equivalent to 1/10 the weight used currently in analyses, separates and recovers the dioxins in purified extract of blood serum. Furthermore, changes in the background level in the general population were clarified by monitoring the dioxin concentrations in human blood. The dioxin concentrations and ratios in blood in the general population remained at a tolerable level for three months. Therefore, the blood serum was available for the detection of a remarkable elevation in dioxins level considered to be indicative of contamination due to high-density exposure.     

Morpho-functional defences of Mediterranean sea urchins,<Emphasis Type="Italic"> Paracentrotus lividus</Emphasis> and<Emphasis Type="Italic"> Arbacia lixula</Emphasis>, against fish predators

Morpho-functional features potentially involved in defence mechanisms against fish predators (i.e. attachment tenacity, spine length, and test robustness and thickness) have been assessed in two Mediterranean sea urchins, Paracentrotus lividus and Arbacia lixula. All four morpho-functional features were significantly and positively related to individual size for both species of sea urchins. Test robustness (i.e. static load needed to break sea urchin tests) was significantly greater for A. lixula (from 3,450 to 15,000 g depending on size) than for P. lividus (1,180–11,180 g). Attachment tenacity (i.e. force needed to dislodge sea urchins from the rocky substrate) was greater in A. lixula (280–3,300 g) than in P. lividus (110–1,450 g), and the difference tended to decrease in relation to smaller sea urchin size. Spine length was greater in A. lixula (1.5–2.9 cm) than in P. lividus (0.5–2.3 cm), but the difference decreased for larger sea urchin size. Test thickness was slightly greater (but not significantly) in A. lixula (0.35–1.10 mm) than in P. lividus (0.12–0.90 mm). These results provide evidence that morpho-functional features of sea urchins could be involved in affecting predation rates by fishes upon P. lividus and A. lixula, with potential implications for the population structure and distribution patterns of the two sea urchins in shallow rocky reefs.Communicated by R. Cattaneo-Vietti, Genova     

Shedding light on a neglected area: a new approach to knowledge creation

Awareness is needed of sustainability issues that are currently neglected but potentially important. A computer-based approach can highlight unconscious and neglected areas because it can structure vast amounts of knowledge. In this article, we propose a methodology to perceive unconscious areas of sustainability with the support of a computer-based approach, which creates a matrix, named the recognized-unrecognized matrix, which highlights both local and globally neglected problems. A case study is conducted to consider the potential contribution of the aviation industry to sustainability issues. We demonstrate that a citation network analysis is an effective methodology to chart the recognized-unrecognized matrix. We highlight issues of water use in the aviation industry by designing an innovative water and air circulation system, which significantly reduces water and fuel consumption on board airplane flights. We also suggest a new approach to integrating both explicit and tacit knowledge to enable knowledge creation.     

Effects of artificial eutrophication on the metabolism of the Japanese oyster Crassostrea gigas

The morphology of the primary tube feet in 15 species of comatulid (unstalked) crinoids from coral reefs in the Palau Islands and Lizard Island, Great Barrier Reef, was investigated using close-up underwater photographs of the tube feet taken in the natural habitat. Measurements of length of the tube feet and their spacing along the pinnule were taken from these photographs. Tube feet of species of the family Comasteridae have a mean length of 0.75 mm and a mean spacing of 6 tube feet mm^-1. Tube feet of non-comasterid species occurring in the same environments have a mean length of 0.55 mm and a mean spacing of about 8 tube feet mm^-1. The relationship between spacing and length of the tube feet is highty significant for both the Palau and Lizard Island samples (P<0.01). Species having longer and more widely spaced tube feet live partly concealed within the infrastructure of the reef and hold the arms and pinnules in a multidirectional posture. Species having shorter and more closely spaced tube feet perch on top of reef pinnacles or alcyonarians and form planar filtration fans normal to unidirectional currents or wave oscillations. Longer and more widely spaced tube feet in species dwelling within the reef infrastructure provide more efficient filtration in the slow, meandering flow prevailing there. Closer spacing of the tube feet in species exposed to near-mainstream flow provides a more efficient filtration mechanism at higher flow velocities. Reduced length of the tube feet in these species may be a consequence of closer spacing of the pinnules. Differentiation of these co-occurring species in spacing and length of the tube feet implies differentiation in food particles captured. This may in some cases constitute resource partitioning. Most species which overlap in living habits are significantly different in spacing and length of the tube feet.     

Maternal provisioning of sequestered defensive steroids by the Asian snake <Emphasis Type="Italic">Rhabdophis tigrinus</Emphasis>

Summary.   Rhabdophis tigrinus obtains defensive steroids (bufadienolides) from its diet and sequesters those compounds in specialized structures on its neck known as nuchal glands. Hatchling snakes lacking these steroids must acquire them from toads consumed as prey. Here we show that females provision bufadienolides to their offspring in amounts correlated to the quantity in their own nuchal glands; thus, chemically protected mothers produce defended offspring. Bufadienolides can be provisioned to embryos via deposition in yolk and by transfer across the egg membranes within the oviducts. Maternally provisioned bufadienolides persist in the nuchal glands of juvenile snakes from the time of hatching in late summer until the following spring, when toads of ingestible size become abundant. Therefore, maternal provisioning may provide chemical protection from predators for young R. tigrinus in the absence of dietary sources of bufadienolides.     

Carbon nanotube-like materials in the exhaust from a diesel engine using gas oil/ethanol mixing fuel with catalysts and sulfur

Particulate matter from a diesel engine, including soot and carbon nanomaterials, was collected on a sampling holder and the structure of the materials was studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). As a result of employing gas oil/ethanol mixing fuel with sulfur and ferrocene/molybdenum as catalyst sources, formation of carbon nanotubes (CNT)-like materials in addition to soot was observed in the exhaust gas from a diesel engine. It was revealed that CNT-like materials were included among soot in our system only when the following three conditions were satisfied simultaneously: high ethanol fraction in fuel, high sulfur loading, and presence of catalyst sources in fuel. This study confirmed that if at least one of these three conditions was not satisfied, CNT-like materials were not observed in the exhaust from a diesel engine. These experimental results shown in this work provide insights into understanding CNT-like material formation mechanism in a diesel engine.

Implications: Recent papers reported that carbon nanotube-like materials were included in the exhaust gas from engines, but conditions for carbon nanotube-like material formation have not been well studied. This work provides the required conditions for carbon nanotube-like material growth in a diesel engine, and this will be helpful for understanding the carbon nanotube-like material formation mechanism and taking countermeasures to preventing carbon nanotube-like material formation in a diesel engine.     

Decomposition and removal of ionic liquid in aqueous solution by hydrothermal and photocatalytic treatment

We demonstrated a complete decomposition method for ionic liquids (ILs; organic cation part: butyl-methyl or ethyl-methyl imidazolium, and inorganic anion part: PF₆ ⁻, BF₄ ⁻ or Br⁻) in aqueous media by combining a hydrothermal mineralization method with a photocatalytic decomposition (PD) method. As a result, the hydrothermal treatment with Ca(OH)₂ mineralizer could effectively remove the inorganic anion part, such as PF₆ ⁻ or BF₄ ⁻ and the PD could decompose the organic cation part effectively. Therefore, the detoxification of ILs in aqueous media was accomplished by the present method.