142 research outputs found
On PP Left-branch Extraction in Japanese
This paper provides an analysis of hitherto unnoticed data concerning left-branch extraction of PPs (PP LBE) in Japanese. While (leftward) LBE of nominals (NP LBE) is impossible in Japanese (see Kato 2007 and Nomura and Hirotsu 2005, among others), PP LBE is in fact allowed. The proposed analysis crucially relies on a specific definition of phases and Watanabe’s (2010) suggestion that the so-called genitive marker –no in fact has a dual status. It is also suggested that PP LBE is an instance of overt Wh-movement (cf. Takahashi 1993, 1994)
LF Intervention Effects and Nominative Objects in Japanese
This paper provides new data to tease apart existing analyses of the wide scope behavior of nominative objects in the Japanese potential construction. An object can get nominative or accusative Case in the Japanese potential construction (Kuno 1973). Significantly, only nominative objects can take scope over the potential suffix (Koizumi 1994, Nomura 2005, Sano 1983, Tada 1992, a.o.). There are at least three possible analyses to capture the wide scope behavior of nominative objects. First, nominative objects move to the Spec of TP, in which case nominative objects c-command the potential suffix (Case-movement analysis: Koizumi 1994, Nomura 2005, a.o. cf. Tada 1992). Second, nominative objects are base-generated in a position above the potential suffix (base-generation approach: Saito and Hoshi 1998, Takano 2003, a.o.). Third, the focus particle in nominative objects undergoes covert A’-movement (covert A’ movement approach: Bobaljik and Wurmbrand 2007, Takahashi 2010. cf. Sano 1985). There is one set of data concerning adjuncts, which favors the latter two approaches (Bobaljik and Wurmbrand 2007, Saito and Hoshi 1998, Takahashi 2010). We provide a new set of data to distinguish the two approaches. In particular, we show that the wide scope behavior of nominative objects is subject to LF intervention effects, which have been observed for Wh-constructions (Hoji 1985). As LF intervention effects are often analyzed in terms of covert movement of Wh-phrases (Beck 1997, Hoji 1985, Tanaka 1997), we conclude that movement is implicated in the wide scope behavior of nominative objects. As the base-generation approach involves no movement, we are lead to choose the covert A’-movement hypothesis over the base-generation approach
Automated closed-chamber measurements of methane fluxes from intact leaves and trunk of Japanese cypress
Continuous in situ measurements of methane (CH4) fluxes from intact leaves and trunk of Japanese cypress (Chamaecyparis obtusa Sieb. et Zucc) were conducted in a temperate forest from August 2009 to August 2010. An automated closed-chamber system, which was used to evaluate CO2 exchange between the atmosphere and forest ecosystems, was coupled to a laser-based instrument to monitor CH4 concentrations. Temporal changes in CH4 concentrations from the foliage and trunk were measured at one-second intervals during chamber closure to determine CH4 fluxes between the leaf and trunk surfaces and the atmosphere. While recent studies have suggested that some plants emit CH4 under aerobic conditions, emission or uptake of CH4 in detectable amounts with our experimental system, by intact leaves or the trunk of C. obtusa, was not significantly observed throughout the measurement period
JAXA-SMASH Program: JAXA\u27s New Co-Creation Program for Small Satellite Missions
JAXA-SMASH (JAXA-Small Satellite Rush) Program is a research and development program that encourages universities, private companies and JAXA to collaborate to realize small satellite missions utilizing commercial small launch opportunities, and to diversify transportation services in Japan
One year of continuous measurements of soil CH4 and CO2 fluxes in a Japanese cypress forest: Temporal and spatial variations associated with Asian monsoon rainfall
We examined the effects of Asian monsoon rainfall on CH[4] absorption of water-unsaturated forest soil. We conducted a 1 year continuous measurement of soil CH[4] and CO[2] fluxes with automated chamber systems in three plots with different soil characteristics and water content to investigate how temporal variations in CH[4] fluxes vary with the soil environment. CH[4] absorption was reduced by the “Baiu” summer rainfall event and peaked during the subsequent hot, dry period. Although CH[4] absorption and CO[2] emission typically increased as soil temperature increased, the temperature dependence of CH[4] varied more than that of CO[2], possibly due to the changing balance of activities between methanotrophs and methanogens occurring over a wide temperature range, which was strongly affected by soil water content. In short time intervals (30 min), the responses of CH[4] and CO[2] fluxes to rainfall were different for each plot. In a dry soil plot with a thick humus layer, both fluxes decreased abruptly at the peak of rainfall intensity. After rainfall, CO[2] emission increased quickly, while CH[4] absorption increased gradually. Release of accumulated CO[2] underground and restriction and recovery of CH[4] and CO[2] exchange between soil and air determined flux responses to rainfall. In a wet soil plot and a dry soil plot with a thinner humus layer, abrupt decreases in CH[4]fluxes were not observed. Consequently, the Asian monsoon rainfall strongly influenced temporal variations in CH[4] fluxes, and the differences in flux responses to environmental factors among plots caused large variability in annual budgets of CH[4] fluxes
Measurement of methane flux over an evergreen coniferous forest canopy using a relaxed eddy accumulation system with tuneable diode laser spectroscopy detection
Very few studies have conducted long-term observations of methane (CH4) flux over forest canopies. In this study, we continuously measured CH4 fluxes over an evergreen coniferous (Japanese cypress) forest canopy throughout 1 year, using a micrometeorological relaxed eddy accumulation (REA) system with tuneable diode laser spectroscopy (TDLS) detection. The Japanese cypress forest, which is a common forest type in warm-temperate Asian monsoon regions with a wet summer, switched seasonally between a sink and source of CH4 probably because of competition by methanogens and methanotrophs, which are both influenced by soil conditions (e.g., soil temperature and soil moisture). At hourly to daily timescales, the CH4 fluxes were sensitive to rainfall, probably because CH4 emission increased and/or absorption decreased during and after rainfall. The observed canopy-scale fluxes showed complex behaviours beyond those expected from previous plot-scale measurements and the CH4 fluxes changed from sink to source and vice versa
Upper Limit on Gravitational Wave Backgrounds at 0.2 Hz with Torsion-bar Antenna
We present the first upper limit on gravitational wave (GW) backgrounds at an
unexplored frequency of 0.2 Hz using a torsion-bar antenna (TOBA). A TOBA was
proposed to search for low-frequency GWs. We have developed a small-scaled TOBA
and successfully found {\Omega}gw(f) < 4.3 \times 1017 at 0.2 Hz as
demonstration of the TOBA's capabilities, where {\Omega}gw (f) is the GW energy
density per logarithmic frequency interval in units of the closure density. Our
result is the first nonintegrated limit to bridge the gap between the LIGO band
(around 100 Hz) and the Cassini band (10-6 - 10-4 Hz).Comment: 4 pages, 5 figure
Methane exchange in a poorly-drained black spruce forest over permafrost observed using the eddy covariance technique
Ecosystem-scale methane (CH4) exchange was observed in a poorly-drained black spruce forest over permafrost in interior Alaska during the snow-free seasons of 2011–2013, using the eddy covariance technique. The magnitude of average CH4 exchange differed depending on wind direction, reflecting spatial variation in soil moisture condition around the observation tower, due to elevation change within the small catchment. In the drier upper position, the seasonal variation in CH4 emission was explained by the variation in soil water content only. In the wetter bottom, however, in addition to soil temperature and soil water content, seasonal thaw depth of frozen soil was also an important variable explaining the seasonal variation in CH4 exchange for this ecosystem. Total snow-free season (day of year 134–280) CH4 exchanges were 12.0 ± 1.0, 19.6 ± 3.0, and 36.6 ± 4.4 mmol m−2 season−1 for the drier upper position, moderately wet area, and wetter bottom of the catchment, respectively. Observed total season CH4 emission was nearly one order smaller than those reported in other northern wetlands, due probably to the relatively low ground water level and low soil temperature. The interannual variation of total snow-free season CH4 emission in the wetter bottom of the catchment was influenced by the amount of rainfall and thaw depth. On the other hand, in the drier upper position the amount of rainfall did not strongly affect the total season CH4 emission. Different responses of CH4 exchange to environmental conditions, depending on the position of a small catchment, should be considered when estimating the spatial variation in CH4 exchange accurately in ecosystems over permafrost.ArticleAGRICULTURAL AND FOREST METEOROLOGY. 214(0):157-168 (2015)journal articl
Insights into the mechanism of diurnal variations in methane emission from the stem surfaces of Alnus japonica
木の中にガスパイプライン? --ガス漏れの場所を特定せよ!--. 京都大学プレスリリース. 2022-07-15.Recent studies have suggested that in certain environments, tree stems emit methane (CH₄). This study explored the mechanism of CH₄ emission from the stem surfaces of Alnus japonica in a riparian wetland. Stem CH₄ emission rates and sap flux were monitored year-round, and fine-root anatomy was investigated. CH₄ emission rates were estimated using a closed-chamber method. Sap flux was measured using Granier-type thermal dissipation probes. Root anatomy was studied using both optical and cryo-scanning electron microscopy. CH₄ emissions during the leafy season exhibited a diurnally changing component superimposed upon an underlying continuum in which the diurnal variation was in phase with sap flux. We propose a model in which stem CH₄ emission involves at least two processes: a sap flux-dependent component responsible for the diurnal changes, and a sap flux-independent component responsible for the background continuum. The contribution ratios of the two processes are season-dependent. The background continuum possibly resulted from the diffusive transport of gaseous CH₄ from the roots to the upper trunk. Root anatomy analysis indicated that the intercellular space of the cortex and empty xylem cells in fine roots could serve as a passageway for transport of gaseous CH₄
- …