Worm-like carbon shell chains produced from wood

Large-scale utilization of wood which command absolute majority in biomass for functional carbon precursors contributes to reduce greenhouse effect. Wood char generally has a limit on material usage because of its non-graphitic structure^1^, so we developed a new functional wood char by iron-, or nickel-catalyzed carbonization, which has a graphite-like structure with mesopores good for electroconductivity and liquid phase adsorption capacity for macro molecules^2-5^. However the fine structure of the wood char is still not clear. Here we report more than 70 wt % of iron-catalyzed wood char is filled with chained carbon shells formed by 3~20 defective stacking layers of carbon hexagonal planes, which look like nanometer-sized worms swarm. We name them "carbon shell chains". The discussion of the formation mechanism reveals that the wood cell wall plays an important role for their efficient production. They are stable at 1800 ºC under vacuum, but in air, burn under 600 ºC, and are perfectly conversed into hydrogen and carbon monoxide in a short time by steam at 900 ºC. The control of their decomposition will bring out a new talent in the wood char as a big source of supply for nano-graphite or nano-graphene, for which nanometer size and edge effects have recently attracted considerable attention^6^. In addition, a simple and easy preparation of carbon shell chains implies that they may be naturally produced on or in the earth rich in iron, and might be misinterpreted as nano-worms, though most of them may decompose into organic gases

The role of web sharing, species recognition and host-plant defence in interspecific competition between two herbivorous mite species

When competing with indigenous species, invasive species face a problem, because they typically start with a few colonizers. Evidently, some species succeeded, begging an answer to the question how they invade. Here, we investigate how the invasive spider mite Tetranychus evansi interacts with the indigenous species T. urticae when sharing the solanaceous host plant tomato: do they choose to live together or to avoid each other’s colonies? Both species spin protective, silken webs on the leaf surfaces, under which they live in groups of con- and possibly heterospecifics. In Spain, T. evansi invaded the non-crop field where native Tetranychus species including T. urticae dominated. Moreover, T. evansi outcompetes T. urticae when released together on a tomato plant. However, molecular plant studies suggest that T. urticae benefits from the local down-regulation of tomato plant defences by T. evansi, whereas T. evansi suffers from the induction of these defences by T. urticae. Therefore, we hypothesize that T. evansi avoids leaves infested with T. urticae whereas T. urticae prefers leaves infested by T. evansi. Using wild-type tomato and a mutant lacking jasmonate-mediated anti-herbivore defences, we tested the hypothesis and found that T. evansi avoided sharing webs with T. urticae in favour of a web with conspecifics, whereas T. urticae more frequently chose to share webs with T. evansi than with conspecifics. Also, T. evansi shows higher aggregation on a tomato plant than T. urticae, irrespective of whether the mites occur on the plant together or not

Acute effects of difference in glucose intake on arterial stiffness in healthy subjects

Background: Post-prandial hyperglycemia is associated with higher cardiovascular risk, which causes arterial stiffening and impaired function. Although post-prandial increases in blood glucose are proportional to the level of intake, the acute effects of different glucose intakes on arterial stiffness have not been fully characterized. The present study aimed to determine the acute effects of differences in glucose intake on arterial stiffness. Methods: Six healthy middle-aged and elderly individuals (mean age, 60.0 ± 12.1 years) were orally administered 15, 20, and 25 g of glucose on separate days in a randomized, controlled, cross-over fashion. Brachial-ankle pulse wave velocity, heart-brachial pulse wave velocity, cardio-ankle vascular index, brachial and ankle blood pressure, heart rate, and blood glucose and serum insulin concentrations before and 30, 60, and 90 min after glucose ingestion were measured. Results: Compared to baseline, brachial-ankle pulse wave velocity was higher at 30, 60 and 90 min after ingestion of 25 g glucose, and higher at 90 min after ingestion of 20 g glucose, but at no time points after ingestion of 15 g. Cardio-ankle vascular index was higher at 60 min than at baseline after ingestion of 25 g glucose, but not after ingestion of 15 or 20 g. Conclusions: These results suggest that brachial-ankle pulse wave velocity and cardio-ankle vascular index is affected by the quantity of glucose ingested. Proposed presently is that glucose intake should be reduced at each meal to avoid increases in brachial-ankle pulse wave velocity and cardio-ankle vascular index during acute hyperglycemia

Function of the web box as an anti-predator barrier in the spider mite, Schizotetranychus recki

Spider mites inhabiting Sasa bamboo show considerable variation in traits believed to be the result of coevolution between predator and prey. In Schizotetranychus recki Ehara inhabiting the hairy leaves of a dwarf bamboo, Sasa senanensis, all quiescent stages, including eggs, appear within web boxes in the leaf hairs of their host plant, and this habit is thought to be a trait involved in predator avoidance. To test this hypothesis, the survival rates of S. recki eggs inside a web box and those freed of a web box were assessed in relation to six predator species that co-occur with the spider mite in the field. The results clearly show that the webbing behavior (web box) of S. recki has a function in avoiding five predator species. However, one predator species, Agistemus summersi Ehara, preyed more on eggs protected by a web box. This suggests that this predator species has a special trait to overcome the nest barriers

Long range transport of PAHs with Asian dust

金沢大学大学院自然科学研究科Promoting Environmental Pesearch in Pan-Japan Sea Area : Young Researchers\u27 Network, Schedule: March 8-10,2006,Kanazawa Excel Hotel Tokyu, Japan, Organized by: Kanazawa University 21st-Century COE Program, Environmental Monitoring and Prediction of Long- & Short- Term Dynamics of Pan-Japan Sea Area ; IICRC(Ishikawa International Cooperation Research Centre), Sponsors : Japan Sea Research ; UNU-IAS(United Nations University Institute of Advanced Studies)+Ishikawa Prefecture Government ; City of Kanazaw

Seasonal Deposition Fluxes of Polycyclic Aromatic Hydrocarbons (PAHs) in Lake Biwa, Japan

金沢大学大学院自然科学研究科金沢大学環日本海域環境研究センター地球環境計測研究部門北海道大学大学院地球環境科学研究院Seasonal deposition fluxes of polycyclic aromatic hydrocarbons (PAHs) in the North Basin of Lake Biwa were investigated by monthly collecting sediment trap samples through a year from July 2003. Average deposition flux of total PAHs was 75 ng cm-2 year-1, similar to those for other rural area. Deposition fluxes of PAHs did varied seasonally. In the vertical mixing period of the lake, late autumn to early spring, the fluxes of less volatile PAHs were enhanced while those for volatile PAHs were not. The size difference of particles associated with volatile and less volatile PAHs caused the seasonal variation of the fluxes. Oil discharge from water delivery equipments may contribute the fluxes of volatile PAHs in summer to autumn. © 2008 Springer Science+Business Media B.V

Measuring sleep quality and autonomic nervous function

The purpose of this study was to determine the relationship between quality of sleep and autonomic nervous functioning in healthy adult Japanese women using three measures, namely, the Pittsburgh Sleep Quality Index (PSQI) for subjective assessment of sleep quality, actigraphy for objective assessment of sleep, and heart rate variability using high frequency and low frequency domains. Participants were 31 healthy women in their 20s to 40s who met the selection criteria, including having normal monthly menstrual periods. Participants were categorized as good or poor sleepers according to their PSQI score. Median correlation coefficients of activity count and high frequency were −0.62 (range −0.43 to −0.84) for good sleepers and −0.45 (range 0.003 to −0.64) for poor sleepers. Good sleepers showed a significantly higher correlation of activity count and high frequency (Z=−2.11, P<0.05). Median correlation coefficients of activity count and low frequency/high frequency were 0.54 (range 0.29–0.73) for good sleepers and 0.41 (range 0.11–0.63) for poor sleepers. The PSQI, actigraphy data, and heart rate variability results showed positive correlations between sleep time as measured by PSQI and duration of inactivity as measured by actigraphy (r=0.446, P<0.05) and sleep time as measured by actigraphy (r=0.377, P<0.05), and a negative correlation between sleep time as measured by PSQI and the correlation coefficients of activity count and high frequency (r=−0.460, P<0.01). These results support the finding that sleep-wake rhythms can be monitored efficiently with actigraphy, providing accurate data that can support the diagnosis of sleeping disorders. Furthermore, actigraphy data were associated with heart rate variability and PSQI findings, but only in subjects who were poor sleepers. Actigraphy is an accurate, efficient, rapid, and inexpensive test for determining objective and subjective sleeping problems, and can also be used in clinical tests for sleep assessment