Importance of rubberwood in wood export of Malaysia and Thailand     

Akira Shigematsu  Nobuya Mizoue  Tsuyoshi Kajisa  Shigejiro Yoshida 《New Forests》2011,41(2):179-189

We examined the contribution of rubberwood to the timber export markets of Malaysia and Thailand. In Malaysia, rubberwood has grown from 26% of total exported wood products in 1998 to 35% in 2007. A high proportion of furniture products (80%) is rubberwood, whereas the contribution of rubberwood to other wooden products is less than 20%. Only 10% of sawn timber and logs is rubberwood. In Thailand, rubberwood contributes to around 60% of total exported wood products, arising from a high share of not only furniture products (70%) but also other wood products (around 50%) and sawn timber and logs, which have increased in share from 40% in 1998 to 79% in 2007. We conclude that the high proportion of rubberwood products in the wood export markets of these two countries is a result of: (1) scarcity of raw wood materials because of strict controls on the logging of natural forests; and (2) governmental support to rubberwood production, including financial support to rubber planters and technical assistance to downstream timber processors.  相似文献   

Estimation of rubberwood production in Cambodia     

Akira Shigematsu  Nobuya Mizoue  Kumiko Ide  Kakada Khun  Muthavy Pheng  Shigejiro Yoshida  Katsuhisa Kohroki  Noriko Sato 《New Forests》2011,42(2):149-162

We estimated the production of rubberwood from 1996 to 2011 in Cambodia. We employed data from interview surveys with three rubberwood processing companies and statistics from estate rubber plantations and wood retailing companies. The result was that the end use of rubberwood in Cambodia was the sawntimber products, being exported to Vietnam and China. The yield rate from rubberwood stumpage into sawn timber was between 11.6 and 14.9%, closely matching the rates of Malaysia and Thailand. The average production of rubberwood roundwood from 1996 to 2011 was 254,697 m³/year, of which sawn timber as well as residuals in secondary processing was 84,559 and 170,138 m³/year, respectively. Although the timber production of Cambodia has declined sharply due to the strict restriction of natural forest logging, rubberwood could explain more than 60% of the domestic industrial roundwood production from 2000. We suggest the necessity of monitoring the expansion of rubber plantations in new rubber producing countries and linking the rubberwood production with the regional wood resource management.  相似文献   

Displacement above the hypocenter of the 2011 Tohoku-Oki earthquake   总被引：3，自引：0，他引：3  

Sato M  Ishikawa T  Ujihara N  Yoshida S  Fujita M  Mochizuki M  Asada A 《Science (New York, N.Y.)》2011,332(6036):1395

The moment magnitude (M(w)) = 9.0 2011 Tohoku-Oki mega-thrust earthquake occurred off the coast of northeastern Japan. Combining Global Positioning System (GPS) and acoustic data, we detected very large sea-floor movements associated with this event directly above the focal region. An area with more than 20 meters of horizontal displacement, that is, four times larger than those detected on land, stretches several tens of kilometers long along the trench; the largest amount reaches about 24 meters toward east-southeast just above the hypocenter. Furthermore, nearly 3 meters of vertical uplift occurred, contrary to observed terrestrial subsidence.  相似文献   

The crystal structure of a sodium galactose transporter reveals mechanistic insights into Na+/sugar symport     

Faham S  Watanabe A  Besserer GM  Cascio D  Specht A  Hirayama BA  Wright EM  Abramson J 《Science (New York, N.Y.)》2008,321(5890):810-814

Membrane transporters that use energy stored in sodium gradients to drive nutrients into cells constitute a major class of proteins. We report the crystal structure of a member of the solute sodium symporters (SSS), the Vibrio parahaemolyticus sodium/galactose symporter (vSGLT). The approximately 3.0 angstrom structure contains 14 transmembrane (TM) helices in an inward-facing conformation with a core structure of inverted repeats of 5 TM helices (TM2 to TM6 and TM7 to TM11). Galactose is bound in the center of the core, occluded from the outside solutions by hydrophobic residues. Surprisingly, the architecture of the core is similar to that of the leucine transporter (LeuT) from a different gene family. Modeling the outward-facing conformation based on the LeuT structure, in conjunction with biophysical data, provides insight into structural rearrangements for active transport.  相似文献   

Teleportation of nonclassical wave packets of light     

Lee N  Benichi H  Takeno Y  Takeda S  Webb J  Huntington E  Furusawa A 《Science (New York, N.Y.)》2011,332(6027):330-333

We report on the experimental quantum teleportation of strongly nonclassical wave packets of light. To perform this full quantum operation while preserving and retrieving the fragile nonclassicality of the input state, we have developed a broadband, zero-dispersion teleportation apparatus that works in conjunction with time-resolved state preparation equipment. Our approach brings within experimental reach a whole new set of hybrid protocols involving discrete- and continuous-variable techniques in quantum information processing for optical sciences.  相似文献   

Molecular mapping for seedling cold tolerance QTLs in rice     

ZhanQingcai SaidoKoji KatoAkira 《农业科学与技术》2003,4(1):8-15

The quantitative trait loci(QTLs)for cold tolerance relative characters were identified with microsatellite markers.Ten QTLs located on chromosome1,3,4,5,6,8,9,11(two)and 12were detected for seedling height at different low temperature.Only 2 of these were detected at the same locus at four environments.1 was significant at three environments.6 were significant at two environments and 1 was significant at one environment.Seven QTLs located on chromosome 1(two),2(two),5,6,8were found for ow temperature chlorosis resistance and five QTLs located on chromosome 3,4,7,8,11resistant to chilling injury.The amount of variation explained by indivdual QTL ranged from 4.85%to 49.34%,There was no linkage relationship among the three characters.which indicates seediling cold tolerance is a complex character and is controlled by different QTLs.  相似文献   

Repeated and sudden reversals of the dipole field generated by a spherical dynamo action     

Li J  Sato T  Kageyama A 《Science (New York, N.Y.)》2002,295(5561):1887-1890

Using long-duration, three-dimensional magnetohydrodynamic simulation, we found that the magnetic dipole field generated by a dynamo action in a rotating spherical shell repeatedly reverses its polarity at irregular intervals (that is, punctuated reversal). Although the total convection energy and magnetic energy alternate between a high-energy state and a low-energy state, the dipole polarity can reverse only at high-energy states where the north-south symmetry of the convection pattern is broken and the columnar vortex structure becomes vulnerable. Another attractive finding is that the quadrupole mode grows, exceeding the dipole mode before the reversal; this may help to explain how Earth's magnetic field reverses.  相似文献   

Orangutan cultures and the evolution of material culture     

van Schaik CP  Ancrenaz M  Borgen G  Galdikas B  Knott CD  Singleton I  Suzuki A  Utami SS  Merrill M 《Science (New York, N.Y.)》2003,299(5603):102-105

Geographic variation in some aspects of chimpanzee behavior has been interpreted as evidence for culture. Here we document similar geographic variation in orangutan behaviors. Moreover, as expected under a cultural interpretation, we find a correlation between geographic distance and cultural difference, a correlation between the abundance of opportunities for social learning and the size of the local cultural repertoire, and no effect of habitat on the content of culture. Hence, great-ape cultures exist, and may have done so for at least 14 million years.  相似文献   

Oxygen isotopic compositions of asteroidal materials returned from Itokawa by the Hayabusa mission     

Yurimoto H  Abe K  Abe M  Ebihara M  Fujimura A  Hashiguchi M  Hashizume K  Ireland TR  Itoh S  Katayama J  Kato C  Kawaguchi J  Kawasaki N  Kitajima F  Kobayashi S  Meike T  Mukai T  Nagao K  Nakamura T  Naraoka H  Noguchi T  Okazaki R  Park C  Sakamoto N  Seto Y  Takei M  Tsuchiyama A  Uesugi M  Wakaki S  Yada T  Yamamoto K  Yoshikawa M  Zolensky ME 《Science (New York, N.Y.)》2011,333(6046):1116-1119

Meteorite studies suggest that each solar system object has a unique oxygen isotopic composition. Chondrites, the most primitive of meteorites, have been believed to be derived from asteroids, but oxygen isotopic compositions of asteroids themselves have not been established. We measured, using secondary ion mass spectrometry, oxygen isotopic compositions of rock particles from asteroid 25143 Itokawa returned by the Hayabusa spacecraft. Compositions of the particles are depleted in (16)O relative to terrestrial materials and indicate that Itokawa, an S-type asteroid, is one of the sources of the LL or L group of equilibrated ordinary chondrites. This is a direct oxygen-isotope link between chondrites and their parent asteroid.  相似文献   

HPLC fluorometric determination of natural phytoplankton phycocyanin and its usefulness as cyanobacterial biomass in highly eutrophic shallow lake     

Akira Otsuki  Takehiko Omi  Shinya Hashimoto  Morihiro Aizaki  Noriko Takamura 《Water, air, and soil pollution》1994,76(3-4):383-396

A method for HPLC determination of phycocyanin in phytoplankton samples using gelchromatography with a fluorescence detector was developed to examine the use of phycocyanin as an index of the appearance and progress of cyanobacterial blooms in highly eutrophic lake. At least two types of phycocyanin with different molecular weights, each spectroscopically different from phycoerythrin and allophycocyanin, were found in natural phytoplankton samples. Changes in phycocyanin concentrations were clearly coupled to changes in chlorophyll-a concentrations during June to October while cyanobacterial blooms were occurring. The chlorophyll-a to phycocyanin relationship was linear at chlorophyll-a concentrations of less than 250 μg L^?1. The relationship between cyanobacterial carbon and phycocyanin concentration was also linear, suggesting that phycocyanin content may be a useful index of cyanobacterial biomass in highly eutrophic lakes where large cyanobacterial blooms occur.  相似文献