Showing papers by "Utsunomiya University published in 2006"

Testing metabolic ecology theory for allometric scaling of tree size, growth and mortality in tropical forests

Abstract: The theory of metabolic ecology predicts specific relationships among tree stem diameter, biomass, height, growth and mortality. As demographic rates are important to estimates of carbon fluxes in forests, this theory might offer important insights into the global carbon budget, and deserves careful assessment. We assembled data from 10 oldgrowth tropical forests encompassing censuses of 367 ha and > 1.7 million trees to test the theory’s predictions. We also developed a set of alternative predictions that retained some assumptions of metabolic ecology while also considering how availability of a key limiting resource, light, changes with tree size. Our results show that there are no universal scaling relationships of growth or mortality with size among trees in tropical forests. Observed patterns were consistent with our alternative model in the one site where we had the data necessary to evaluate it, and were inconsistent with the predictions of metabolic ecology in all forests.

Exemplary Teacher Induction: An international review

Abstract: How does one become an effective teacher? What can be done to stem high attrition rates among beginning teachers? While many teachers are left to ‘sink or swim’ in their first year—learning by trial and error, there remain a number of outstanding examples of collaboration and collegiality in teacher induction programs. Analysis of the most exemplary teacher induction programs from Australia, Britain, Canada, France, Germany, Japan, New Zealand and the United States revealed common attributes and exceptional features. The most successful teacher induction programs reported here include opportunities for experts and neophytes to learn together in a supportive environment promoting time for collaboration, reflection and acculturation into the profession of teaching. Furthermore, several practices unique to specific regions were highlighted. These included extended internship programs, specially trained mentors, comprehensive inservice training and reduced teaching assignments for beginning teachers with an e...

Anisotropy and corotation of galactic cosmic rays.

Abstract: The intensity of Galactic cosmic rays is nearly isotropic because of the influence of magnetic fields in the Milky Way. Here, we present two-dimensional high-precision anisotropy measurement for energies from a few to several hundred teraelectronvolts (TeV), using the large data sample of the Tibet Air Shower Arrays. Besides revealing finer details of the known anisotropies, a new component of Galactic cosmic ray anisotropy in sidereal time is uncovered around the Cygnus region direction. For cosmic-ray energies up to a few hundred TeV, all components of anisotropies fade away, showing a corotation of Galactic cosmic rays with the local Galactic magnetic environment. These results have broad implications for a comprehensive understanding of cosmic rays, supernovae, magnetic fields, and heliospheric and Galactic dynamic environments.

Comparing tropical forest tree size distributions with the predictions of metabolic ecology and equilibrium models

Abstract: Tropical forests vary substantially in the densities of trees of different sizes and thus in above-ground biomass and carbon stores. However, these tree size distributions show fundamental similarities suggestive of underlying general principles. The theory of metabolic ecology predicts that tree abundances will scale as the -2 power of diameter. Demographic equilibrium theory explains tree abundances in terms of the scaling of growth and mortality. We use demographic equilibrium theory to derive analytic predictions for tree size distributions corresponding to different growth and mortality functions. We test both sets of predictions using data from 14 large-scale tropical forest plots encompassing censuses of 473 ha and > 2 million trees. The data are uniformly inconsistent with the predictions of metabolic ecology. In most forests, size distributions are much closer to the predictions of demographic equilibrium, and thus, intersite variation in size distributions is explained partly by intersite variation in growth and mortality.

Catalytic gasification of wood biomass in subcritical and supercritical water

Abstract: Research in biomass gasification with subcritical and supercritical water is reviewed. Catalytic conversion of biomass in sub- and supercritical water is a low-temperature gasification technique that can be carried out from 473 to 973 K. Research is categorized according to temperature and water density, since reaction mechanisms greatly depend on these variables.

Effect of 5-Aminolevulinic Acid on Development and Salt Tolerance of Potato (Solanum tuberosum L.) Microtubers in vitro

Abstract: The effects of 5-aminolevulinic acid (ALA), a key precursor in the biosynthesis of porphyrins such as chlorophyll and heme, on development and salt tolerance of microtubers of two potato (Solanum tuberosum L.) cultivars Jingshi-2 and Zihuabai were examined under in vitro conditions. ALA at 0.3–3 mg/l promoted microtuber formation by increasing the average number, diameter, and fresh weight of microtubers especially under 0.5% NaCl stress conditions, but further increase in ALA concentration resulted in a reduction of microtuber yield irrespective of NaCl stress. Under 1.0% NaCl stress conditions, microtuberization was seriously repressed and could not be restored by the addition of ALA. The accumulation of malondialdehyde in the microtubers treated with 30 mg/l ALA increased by 22% compared to the controls (no salinity), while only a 7% increase was observed when the microtubers were exposed to 0.5% NaCl, indicating that ALA functions as a protectant against oxidative damages of membranes. Under 0.5% NaCl stress conditions, the highest activities of peroxidase and polyphenoloxidase were detected in microtubers treated with ALA at 0.3 and 3 mg/l, being by 73% and by 28% greater than those in the untreated controls, respectively. These results demonstrate that ALA at lower concentrations of 0.3–3 mg/l promotes development and growth of potato microtubers in vitro and enhances protective functions against oxidative stresses, but ALA at 30 mg/l and higher concentrations seems to induce oxidative damage probably through formation and accumulation of photooxidative porphyrins.

Characterization of Strigolactones, Germination Stimulants for the Root Parasitic Plants Striga and Orobanche, Produced by Maize, Millet and Sorghum

Abstract: The germination stimulants for root parasitic plants Striga and Orobanche produced by sorghum (Sorghum bicolor (L.) Moench), maize (Zea mays L.), and pearl millet (Pennisetum typhoideum Rich.) were examined. Characterization of strigolactones in the root exudates from the plants grown hydroponically was conducted by comparing retention times of germination stimulants on reverse phase high performance liquid chromatography (HPLC) with those of synthetic standards, and by using HPLC linked with tandem mass spectrometry (LC/MS/MS). All the plants tested, except for a sorghum cultivar Swarna, were found to exude two major stimulants, 5-deoxy-strigol, which is known as a branching factor for arbuscular mycorrhizal (AM) fungi, and an isomer of strigol, tentatively named sorghumol. Swarna was found to exude 5-deoxy-strigol and strigol. These results imply that 5-deoxy-strigol is one of major germination stimulants of gramineous plants and that major stimulants may differ even among cultivars within the same species.

Novel fish hypothalamic neuropeptides stimulate the release of gonadotrophins and growth hormone from the pituitary of sockeye salmon

Abstract: We recently identified a cDNA encoding three novel fish hypothalamic neuropeptides, having LPXRF-NH(2) from the goldfish brain. In this study, to clarify the physiological functions of these three LPXRFamide peptides (gfLPXRFa-1, -2, and -3), we analysed the localisation and hypophysiotrophic activity of these peptides using sockeye salmon, Oncorhynchus nerka, in which immunoassay systems for several anterior pituitary hormones have been developed. gfLPXRFa-immunoreactive cell bodies were detected in the nucleus posterioris periventricularis of the hypothalamus and immunoreactive fibres were distributed in various brain regions and the pituitary. We also detected gfLPXRFa-immunoreactivity in the pituitary by competitive enzyme-linked immunosorbent assay combined with reversed-phase HPLC. These three gfLPXRFamide peptides stimulated the release of FSH, LH and GH, but did not affect the release of prolactin (PRL) and somatolactin (SL) from cultured pituitary cells. These results suggest that novel fish hypothalamic LPXR-Famide peptides exist in the brain and pituitary of sockeye salmon and stimulate the release of gonadotrophins and GH from the pituitary.

Beam quality factor of higher order modes in a step-index fiber

Abstract: The beam quality factor (or M2-parameter) for linearly polarized (LP)-modes of a step-index fiber is calculated in a closed form, as a function of the fiber V-number. It is shown that M2 sharply peaks for all fiber modes when they are close to cutoff. Particularly simple expressions are derived in the limit Vrarrinfin. Two practically important coherent superpositions of modes are considered for which the degree of degradation of the beam quality due to the higher order mode content is calculated. The reported results can be useful for designing large-core high-power fiber lasers, amplifiers, and fiber-based beam delivery systems, when preservation of the spatial beam quality is important

Long-day suppressed expression of type 2 deiodinase gene in the mediobasal hypothalamus of the saanen goat, a short-day breeder : Implication for seasonal window of thyroid hormone action on reproductive neuroendocrine axis

Abstract: In most animals that live in temperate regions, reproduction is under photoperiodic control. In long-day breeders such as Japanese quail and Djungarian hamsters, type 2 deiodinase (Dio2) plays an important role in the mediobasal hypothalamus, catalyzing the conversion of prohormone T4 to bioactive T3 to regulate the photoperiodic response of the gonads. However, the molecular basis for seasonal reproduction in short-day breeders remains unclear. Because thyroid hormones are also known to be involved in short-day breeders, we examined the effect of an artificial long-day stimulus on Dio2 expression in the male Saanen goat (Capra hircus), a short-day breeder. Dio2 expression was observed in the caudal continuation of the arcuate nucleus, known as the target site for both melatonin and T4 action. In addition, expression of Dio2 and T3 content in the mediobasal hypothalamus was suppressed by artificial long-day conditions, which is the opposite of the results of long-day breeders. Thyroid hormone action on the development of neuroendocrine anestrus is known to be limited to a specific seasonal window. This long-day suppression of Dio2 may provide a mechanism that accounts for the lack of responsiveness to thyroxine during the mid to late anestrus.

Generation of Self‐Assembled 3D Mesostructured SnO2 Thin Films with Highly Crystalline Frameworks

Abstract: Crack-free, mesoporous SnO 2 films with highly crystalline pore walls are obtained by evaporation-induced self-assembly using a novel amphiphilic block-copolymer template ("KLE" type, poly(ethylene-co-butylene)-block-poly(ethylene oxide)), which leads to well-defined arrays of contracted spherical mesopores by suitable heat-treatment procedures. Because of the improved templating properties of these polymers, a facile heat-treatment procedure can be applied whilst keeping the mesoscopic order intact up to 600-650 °C. The formation mechanism and the mesostructural evolution are investigated by various state-of-the-art techniques, particularly by a specially constructed 2D small-angle X-ray scattering setup. It is found that the main benefit from the polymers is the formation of an ordered mesostructure under the drastic conditions of using molecular Sn precursors (SnCl 4 ), taking advantage of the large segregation strength of these amphiphiles. Furthermore, it is found that the crystallization mechanism is different from other mesostructured metal oxides such as TiO 2 . In the case of SnO 2 , a significant degree of crystallization (induced by heat treatment) already starts at quite low temperatures, 250-300 °C. Therefore, this study provides a better understanding of the general parameters governing the preparation of mesoporous metal oxides films with crystalline pore walls.

First events from the CNGS neutrino beam detected in the OPERA experiment

Abstract: The OPERA neutrino detector at the underground Gran Sasso Laboratory (LNGS) was designed to perform the first detection of neutrino oscillations in appearance mode, through the study of nu_mu to nu_tau oscillations. The apparatus consists of a lead/emulsion-film target complemented by electronic detectors. It is placed in the high-energy, long-baseline CERN to LNGS beam (CNGS) 730 km away from the neutrino source. In August 2006 a first run with CNGS neutrinos was successfully conducted. A first sample of neutrino events was collected, statistically consistent with the integrated beam intensity. After a brief description of the beam and of the various sub-detectors, we report on the achievement of this milestone, presenting the first data and some analysis results.

Prospects for multifunctionality of paddy rice cultivation in Japan and other countries in monsoon Asia

Abstract: This paper presents a study carried out by a group of Japanese researchers to critically review past researches and discussions on the multifunctionality of paddy rice cultivation, with the aim of describing the current status of the subject and providing options and potentials for future research and practices. The review was of over 200 documented articles on the major external functions. The results of this study revealed that the importance of multifunctionality is well perceived in Japan. The methodologies to measure and estimate the magnitude have been established for most functions. However, there is a need for more cases, to integrate all the functions at the local or regional scale to represent site-specific characteristics of multifunctionality. There is also a need to develop management practices to sustain and enhance the positive multifunctionality of paddy rice cultivation while minimizing negative effects to the environment, which may be brought into the agricultural policies. Except for Korea, Taiwan, and Japan, there are slightly different notions on multifunctionality in other monsoon Asia countries, but the gap in this notion is reducing following recent international activities.

Effect of Water Density on the Gasification of Lignin with Magnesium Oxide Supported Nickel Catalysts in Supercritical Water

Abstract: Gasification of lignin biomass model compounds was examined in the presence of magnesium oxide supported nickel catalysts (Ni/MgO) in sub- and supercritical water from 523 to 673 K. The main gas products were methane, carbon dioxide, and hydrogen. The amount of gases produced increased with an increase in nickel loading on magnesium oxide. The highest total gas yield in a carbon basis was 78% with 20 wt % Ni/MgO catalyst at 673 K and 0.3 g/cm3 water density. In this system, the metal and support of Ni/MgO probably play different roles in gasification that MgO decomposed lignin to reactive intermediates and nickel promoted reaction between intermediates and water to form gases. The yield of methane and carbon dioxide increased with increasing water density but then decreased and leveled out to constant values, which indicates that water density affected the reaction kinetics.

On slant curves in sasakian 3-manifolds

Abstract: A classical theorem by Lancret says that a curve in Euclidean 3-space is of constant slope if and only if its ratio of curvature and torsion is constant. In this paper we study Lancret type problems for curves in Sasakian 3-manifolds.

A case study on the costs and the fuel consumption of harvesting, transporting, and chipping chains for logging residues in Japan

Abstract: The objective of this study is to examine the feasibility of a harvesting and transporting system for logging residues including the cost, energy, and carbon dioxide (CO2) effectiveness of fossil energy substitution with logging residues in Japan. “A harvesting and transporting system for logging residues” was constructed with reference to some European countries, where the utilization of bioenergy is making steady progress, and examined based on field experiments in Japanese forestry. The feasibility of the system was discussed from the standpoints of cost, energy, and CO2, and the system was compared with those of European countries. Concerning the system, it is desirable that the process of chipper comminuting should be incorporated into the system as early as possible. Although such a system is not particularly feasible in Japan from the standpoint of cost, it is suggested that it should be possible for Japan to reduce the domestic CO2 emissions by utilizing logging residues as alternative energy resources. A comparison with the European countries and a preliminary sensitivity analysis to the system demonstrate that the technical development to reduce the total cost, e.g., improving the forwarding and transporting efficiency, is essential for realizing bioenergy utilization in Japan.

Estimation of Drought Tolerance Based on Leaf Temperature in Upland Rice Breeding

Abstract: The evaluation of drought tolerance based on the leaf temperature was examined in upland rice breeding. The relationships of the leaf temperature with the transpiration and photosynthetic rates were observed in upland and lowland rice varieties under upland cultivation in 1995, 1996 and 1997. The leaf temperature of the upland rice varieties was lower than that of the lowland rice varieties. Their transpiration and photosynthetic rates were highly correlated with the leaf temperature, measured using an infrared radiation thermometer or portable photosynthesis gas analyzing system in all the three years. The leaf temperature also showed a significant relationship with the grain yield tested in 1995. It is considered that rice varieties with a lower leaf temperature can maintain high transpiration and photosynthetic rates as well as produce a high yield under upland conditions. In addition, there was a significant positive correlation between the leaf temperature and root growth recorded by the trench method. Upland rice varieties with deep rooting showed lower leaf temperatures than those with a shallower root system. On the other hand, in the comparison of leaf temperature in varietal groups of breeding materials, the upland rice lines with medium-late maturity showed the lowest temperature, followed by the early maturing lines and lines for cultivation with sprinkler irrigation. This tendency was in agreement with the general degree of drought tolerance of individual varietal groups. To analyze the mode of inheritance of the leaf temperature, the parent-offspring correlation of leaf temperature measured using an infrared radiation thermometer was examined in breeding materials. Leaf temperature was compared between the progeny lines (F4 generation) of the upland rice variety Kantomochi168 with a high drought tolerance and the upland rice variety Norinmochi4 with a medium drought tolerance. Kantomochi168 progeny showed a lower leaf temperature than Norinmochi4. A similar tendency was confirmed in the F5 generation in the following year. Significant parental-offspring correlation (r = 0.812**) was observed between F4 and F5. Since the leaf temperature of the upland rice progeny may display a relatively higher inheritance, the leaf temperature is, therefore, considered to be a useful indicator to estimate the drought tolerance for line selection in upland rice breeding.

Effect of a laser prepulse on fast ion generation in the interaction of ultra-short intense laser pulses with a limited-mass foil target

Abstract: Fast electrons generated in ultra-intense laser interaction with a solid target can produce multi-MeV ions from laser-induced plasmas. These fast ions can have different applications ranging from ion implantation to nuclear reactions. The most important parameter is the efficiency of fast ion production. An analytical model and particle-in-cell simulations were employed to examine acceleration mechanisms that can provide an optimal plasma density distribution due to a laser prepulse. We considered the acceleration of ions leaving a plasma layer with different density gradients, from a step-like overdense plasma to an underdense plasma with a smooth density gradient. The effects of the plasma initial scale length and density on the ion acceleration were analysed, and we found that the optimal case should have some plasma parameters. It is shown that overdense plasmas provide a higher density of accelerated ion energy than underdense plasmas at intensities below 1019 W cm−2.

The assembly and maintenance of heterochromatin initiated by transgene repeats are independent of the RNA interference pathway in mammalian cells.

Abstract: A role for the RNA interference (RNAi) pathway in the establishment of heterochromatin is now well accepted for various organisms. Less is known about its relevance and precise role in mammalian cells. We previously showed that tandem insertion of a 1,000-copy inducible transgene into the genome of baby hamster kidney (BHK) cells initiated the formation of an extremely condensed chromatin locus. Here, we characterized the inactive transgenic locus as heterochromatin, since it was associated with heterochromatin protein 1 (HP1), histone H3 trimethylated at lysine 9, and cytosine methylation in CpG dinucleotides. Northern blot analysis did not detect any transgene-derived small RNAs. RNAi-mediated Dicer knockdown did not disrupt the heterochromatic transgenic locus or up-regulate transgene expression. Moreover, neither Dicer knockdown nor overexpression of transgene-directed small interfering RNAs altered the bidirectional transition of the transgenic locus between the heterochromatic and euchromatic states. Interestingly, tethering of HP1 to the transgenic locus effectively induced transgene silencing and chromatin condensation in a Dicer-independent manner, suggesting a role for HP1 in maintaining the heterochromatic locus. Our results suggest that the RNAi pathway is not required for the assembly and maintenance of noncentromeric heterochromatin initiated by tandem transgene repeats in mammalian cells.

Possible involvement of organic anion transporting polypeptide 1c1 in the photoperiodic response of gonads in birds

Abstract: The photoperiodic response of the gonads requires T3, which is generated photoperiodically from T4 by type 2 iodothyronine deiodinase in the hypothalamus. Although thyroid hormones were long thought to traverse the plasma membrane by passive diffusion due to their lipophilic nature, it is now known that several organic anion transporting polypeptides (Oatp) transport thyroid hormones into target cells. In this study, we have used database searches to isolate DNA sequences encoding members of the chicken Oatp family and constructed a molecular phylogenetic tree. Comprehensive expression analyses using in situ hybridization revealed strong expression of cOatp1c1 and weak expression of cOatp1b1 in the ventro-lateral walls of basal tuberal hypothalamus, whereas expression of four genes (cOatp1a1, cOatp1b1, cOatp1c1, and cOatp3a2) was observed in the choroid plexus. Expression levels of all these genes in both regions were not different between short-day and long-day conditions. Functional expression of cOatp1...

Circadian Clock Mutation in Dams Disrupts Nursing Behavior and Growth of Pups

Abstract: To understand the role of the circadian molecular clock in mouse reproduction, we investigated the daily rhythms associated with nursing and pup growth in Clock-mutant mice maintained under light-dark housing conditions. The daily rhythm associated with the maternal behavior of crouching had a strong diurnal peak and two weak nocturnal peaks in wild-type dams, whereas homozygotes (Clock/Clock) exhibited no significant peaks in activity. Wild-type, but not Clock-mutant, dams showed high, rhythmic levels of prolactin content in serum that corresponded with crouching. Pup body weight increased at a significantly slower rate in Clock-mutant dams compared with wild-type dams under all experimental conditions when the pups ranged from 10-15 in number. Heterozygote dams equally bred wild-type, heterozygote, or homozygote pups. The amount of milk secreted from dams, as calculated by the increase in pup body weight through suckling, was lower in Clock-mutant mothers vs. wild-type mice. When Clock-mutant dams gave birth to more than 10 pups, survival was poor for offspring until the time of weaning. The present results demonstrate that Clock mutation disrupts daily maternal behavior and the growth and survival rate of pups, especially with the breeding of more than 10 pups.

Smoking as a risk factor for visceral fat accumulation in Japanese men.

Abstract: Epidemiological and clinical studies on the lifestyle-related obesity have identified smoking, physical activity and alcohol intake as risk factors for obesity. However, no consensus has yet been reached on the effect of smoking on visceral adiposity. This study was designed to assess whether smoking is associated with the accumulation of visceral fat, glucose and lipid metabolism. The subjects were 450 males aged from 24 to 68 years old, who were examined at the health control center in the regular health check conducted by their company. A self-administered questionnaire was used to ascertain smoking status, daily physical activity and alcohol drinking. The number of Brinkman index as an index for smoking status was positively related to being visceral fat area (VFA). In smokers whose Brinkman index was higher, the percent of subjects with abnormal body mass index, VFA, triglyceride, high density lipoprotein-cholesterol, atherosclerotic index, plasma glucose, immunoreactive insulin, or homeostasis model assessment of insulin resistance (HOMA-IR) was higher than that in non-smokers. When evaluated in terms of age-adjusted odds ratios for incidence of a VFA of 100 cm(2) or greater, alcohol drinking was associated with the highest odds ratio. Smoking, physical inactivity and excessive alcohol drinking were associated with visceral adiposity, and smoking affected glucose and lipid metabolism. In conclusions, these findings suggest that smoking is a risk factor for visceral fat accumulation and deterioration of glucose and lipid metabolism.

Whole-cell arsenite biosensor using photosynthetic bacterium Rhodovulum sulfidophilum. Rhodovulum sulfidophilum as an arsenite biosensor.

Abstract: An arsenite biosensor plasmid was constructed in Escherichia coli by inserting the operator/promoter region of the ars operon and the arsR gene from E. coli and the crtA gene, which is responsible for carotenoid synthesis in the photosynthetic bacterium, Rhodovulum sulfidophilum, into the broad-host-range plasmid vector, pRK415. The biosensor plasmid, pSENSE-As, was introduced into a crtA-deleted mutant strain of R. sulfidophilum (CDM2), which is yellow in culture due to its content of spheroiden (SE) and demethylspheroidene (DMSE). CDM2 containing pSENSE-As changed from yellow to red by the addition of arsenite, which caused enzymatic transformation of SE and DMSE to spheroidenone (SO) and demethylspheroidenone (DMSO). Reverse transcriptase PCR analysis showed that the color change depended on transcription of the crtA gene in pSENSE-As. The color change could be clearly recognized with the naked eye at 5 μg/l arsenite. The biosensor strain did not respond to other metals except for bismuth and antimony, which caused significant accumulation of SO and DMSO in the cells at 60 and 600 μg/l, respectively. This biosensor indicates the presence of arsenite with a bacterial color change without the need to add a special reagent or substrate for color development, enabling this pollutant to be monitored in samples by the naked eye in sunlight, even where electricity is not available.

Autonomous Control for Micro-Flying Robot and Small Wireless Helicopter X.R.B

Abstract: This paper presents autonomous control for Micro-Flying Robot (?FR) and small helicopter X.R.B. In case of natural disaster like earthquake, a MAV will be very effective for surveying the site and environment in dangerous area or narrow space, where human cannot access safely. In addition, it will be a help to prevent secondary disaster. This paper is concerned with autonomous hovering control, guidance control of ?FR, and automatic takeoff and landing control of X.R.B.