We describe a teaching−practice experience of graduate students for industrial arts education cla... more We describe a teaching−practice experience of graduate students for industrial arts education classes given at a junior high school. Naruto University of Education(NUE)has provided a task−oriented study course in which students are responsible for identifying and pursuing educational topics in elementary or secondary schools. In 2013, eight graduate students took part in the program. They have diversified backgrounds other than pedagogy, and are studying for acquiring teacher’s certificates. Prior to teaching a real class, weekly meetings were held for three months to generate and develop a feasible instructional content with teaching materials. The content was determined to be a topic in energy conversion learning from baking bread using Joule’s heat. A teaching plan was drawn up to standardize the educational context for student teachers with different backgrounds. Also, a safety guidance was formulated, taking into account the use of high−electric current. Then, laboratory experi...
Atmosphere and Ocean Research Institute, The University of Tokyo, C llege of Art and Design, Musa... more Atmosphere and Ocean Research Institute, The University of Tokyo, C llege of Art and Design, Musashino Art University, Interactive Research Center of Science, Tokyo Institute of Technology, Graduate School of Education, Naruto University of Education,The Center for Academic Resources and Archives, Botanical Gardens, Tohoku University, National Research Institute for Cultural Properties, Nara, Research Institute for Humanity and Nature
Paleoclimatology and paleoceanography Convener:*Kazuyoshi Yamada(School of Human Sciences, Waseda... more Paleoclimatology and paleoceanography Convener:*Kazuyoshi Yamada(School of Human Sciences, Waseda University), Minoru Ikehara(Center for Advanced Marine Core Research, Kochi University), Tomohisa Irino(Faculty of Environmental Earth Science, Hokkaido University), Yusuke Okazaki(Department of Earth and Planetary Sciences, Graduate School of Science, Kyushu University), Ikuko Kitaba(Kobe University Research Center For Inland Seas), Akihisa Kitamura(Institute of Geosciences, Faculty of Science, Shizuoka University), Masaki Sano(Research Institute for Humanity and Nature), Ryuji Tada(Department of Earth and Planetary Science, Graduate School of Science, The Univeristy of Tokyo), Masakazu Yoshimori(Atmosphere and Ocean Research Institute, University of Tokyo), Chair:Masaki Sano(Research Institute for Humanity and Nature) Mon. Apr 28, 2014 11:00 AM 12:45 PM 501 (5F) We discuss past environmental changes and events at multi-decadal to tectonic timescale toward an understanding of Earth cli...
Elemental carbon (EC) is a combustion product which is composed of rich C and depleted O, H, S, N... more Elemental carbon (EC) is a combustion product which is composed of rich C and depleted O, H, S, N. Biomass burning is major source of Pre-industrial EC, while fossil fuel burning has been the most important source since the 18th century. Black carbon (BC) transfered in the atmosphere as aelosols, including EC have a great impact on the climate. EC is also the second strongest contributor to global warming, and has effect to darken snow and ice surface. On the other hand, aerosols including EC have also negative effect on radiative forcing, which lead cooling. Although it is difficult to evaluate the net EC effect on climate, it is necessary to discriminate EC produced by fossil fuel burning from those from biomass burning. EC is not a single chemical compound, but it can be classified into two types , char and soot. Char is produced by pyrolysis, while soot is formed via gas-to-particle conversion. The char particles which are countable under microscope are called charcoal. There ar...
The beginning of agriculture in Ryukyu Islands goes back to the 10th-12th century (Takamiya and I... more The beginning of agriculture in Ryukyu Islands goes back to the 10th-12th century (Takamiya and Itoh, 2011). Land clearing for farm lands accelerated soil discharge into water systems in Ryukyu Islands due to heavy rain in summer. In a closed bay, finer-grained clastics can remain sub-merged for long periods, causing adverse effects in fishery. In this study we will report on the analytical results for sediment cores recovered from Haneji-naikai. Haneji-naikai is a bay closed by the Yagachi and Okubu Islands. Its maximum water depth is 10 m with the area is 10km . The Nasata river flows into the Haneji-naikai. In 2010 and 2012, 3-m and 24-m long sediment cores were recovered from the center of the bay. These were used to reconstruct the past environmental changes and human activities. The latter longer cores consisted of clay and silt with shell fragments from the surface up to the 16-m depth, while he lower part was composed of gravels. The radiocarbon dates of terrestrial plant fl...
Abstract Rebun is a small island located northwest of Hokkaido Island where hunter-fisher-gathere... more Abstract Rebun is a small island located northwest of Hokkaido Island where hunter-fisher-gatherer cultural traditions continued until the 19th century CE. In this study, we quantified polycyclic aromatic hydrocarbons (PAHs), pentacyclic triterpene methyl ethers (PTMEs), n-fatty acids, and glycerol dialkyl glycerol tetraethers (GDGTs) in sediments from Lake Kushu in northern Rebun Island to reconstruct changes in limnology, the local environment and local to regional fire activities during the past 17,000 years (i.e., 17 ka). The PAH concentration increased from 11 to 10 cal ka BP. PAH and PTME compositions indicate that this change was associated with an increase of fire activity at proximal locations (i.e., the vicinity of Lake Kushu) and a change in the composition of grasses growing around the lake. A peak in PAH concentrations at 6.6–6.0 cal ka BP likely indicates intensive fire activity on Rebun Island. The PAH composition after 6 cal ka BP mainly reflected the combustion of conifers near the lake. The GDGTs, n-fatty acids, perylene, and PTME concentrations were higher around 10 cal ka BP and after 6 cal ka BP compared to the remaining periods, suggesting better preservation of those compounds under lake conditions marked by lower oxygen concentrations.
Proceedings of the National Academy of Sciences of the United States of America, Feb 7, 2017
The lowland Maya site of Ceibal, Guatemala, had a long history of occupation, spanning from the M... more The lowland Maya site of Ceibal, Guatemala, had a long history of occupation, spanning from the Middle Preclassic Period through the Terminal Classic (1000 BC to AD 950). The Ceibal-Petexbatun Archaeological Project has been conducting archaeological investigations at this site since 2005 and has obtained 154 radiocarbon dates, which represent the largest collection of radiocarbon assays from a single Maya site. The Bayesian analysis of these dates, combined with a detailed study of ceramics, allowed us to develop a high-precision chronology for Ceibal. Through this chronology, we traced the trajectories of the Preclassic collapse around AD 150-300 and the Classic collapse around AD 800-950, revealing similar patterns in the two cases. Social instability started with the intensification of warfare around 75 BC and AD 735, respectively, followed by the fall of multiple centers across the Maya lowlands around AD 150 and 810. The population of Ceibal persisted for some time in both cas...
Proceedings of the National Academy of Sciences, 2015
Our archaeological investigations at Ceibal, a lowland Maya site located in the Pasión region, do... more Our archaeological investigations at Ceibal, a lowland Maya site located in the Pasión region, documented that a formal ceremonial complex was built around 950 B.C. at the onset of the Middle Preclassic period, when ceramics began to be used in the Maya lowlands. Our refined chronology allowed us to trace the subsequent social changes in a resolution that had not been possible before. Many residents of Ceibal appear to have remained relatively mobile during the following centuries, living in ephemeral post-in-ground structures and frequently changing their residential localities. In other parts of the Pasión region, there may have existed more mobile populations who maintained the traditional lifestyle of the preceramic period. Although the emerging elite of Ceibal began to live in a substantial residential complex by 700 B.C., advanced sedentism with durable residences rebuilt in the same locations and burials placed under house floors was not adopted in most residential areas unti...
ABSTRACT The Kiso-hinoki (Kiso-Japanese cypress, Chamaecyparis obtusa) woodland underwent severe ... more ABSTRACT The Kiso-hinoki (Kiso-Japanese cypress, Chamaecyparis obtusa) woodland underwent severe deforestation in the early 17th century, then regenerated through conservation during the Edo period. Now, a suitable management strategy is sought in order to maintain its ecological function in the forest. To understand the vegetation changes and human impact, sediment cores were recovered from Lake Tadachi in the Kiso-hinoki cypress woodland in the central uphill region of Honshu island. In addition, stratigraphic pollen analysis on two cores (Nos. 6 and 10) and phytolith analysis on three strata of one core (No. 6) was conducted. The age-depth models were constructed based on 14C dating, greyscale analysis on the sediments, and the increasing level of Cryptomeria pollen (about a.d. 1960) from the pollen profiles. In all periods, the dominant pollen taxa were Cupressaceae and Quercus subgen. Lepidobalanus type. Our analysis indicates that after the commencement of Shikinen-sengu, which is the rebuilding of the Ise Grand Shrine every 20 years, Cupressaceae pollen decreased and the woodland was gradually replaced by Quercus subgen. Lepidobalanus. The percentages of Cupressaceae pollen decreased dramatically and the expansion of secondary woodlands was accompanied by an increase of Quercus subgen. Lepidobalanus in the early 17th century cal. a.d. However, depletion of the woodland was determined from a decrease in concentration of Quercus pollen. The conservation activity during the Edo period and after the Meiji Restoration brought about woodland recovery. However, based on our pollen and phytolith analysis, significant changes to the woodland habitats can be detected. These were probably due to human impacts, most notably in the years after World War II. Four major turning points as the result of human influence were identified: the 10th century, the late 16th century, the Meiji restoration (a.d. 1863), and the end of World War II. The original cypress woodland mixed with deciduous broad-leaved elements has been greatly reduced, preventing future cypress woodland regeneration after World War II.
Dating Carbon Radiocarbon dating is the best way to determine the age of samples that contain car... more Dating Carbon Radiocarbon dating is the best way to determine the age of samples that contain carbon and that are younger than ∼50,000 years, the limit of precision for the method. There are several factors that complicate such age determinations, however, some of the most important of which include variability of the 14 C production in the atmosphere (which affects organic samples whose radiocarbon inventories are derived from atmospheric CO 2 ), surface ocean reservoir effects (which affect marine samples that acquire their radiocarbon signatures from seawater), and variable dead carbon fraction effects (which affect speleothems that derive their carbon from groundwaters). Bronk Ramsey et al. (p. 370 ; see the Perspective by Reimer ) avoid the need to make such assumptions, reporting the 14 C results of sediments from Lake Suigetsu, Japan. Analysis of terrestrial plant macrofossils in annually layered datable sediments yielded a direct record of atmospheric radiocarbon for the ent...
We describe a teaching−practice experience of graduate students for industrial arts education cla... more We describe a teaching−practice experience of graduate students for industrial arts education classes given at a junior high school. Naruto University of Education(NUE)has provided a task−oriented study course in which students are responsible for identifying and pursuing educational topics in elementary or secondary schools. In 2013, eight graduate students took part in the program. They have diversified backgrounds other than pedagogy, and are studying for acquiring teacher’s certificates. Prior to teaching a real class, weekly meetings were held for three months to generate and develop a feasible instructional content with teaching materials. The content was determined to be a topic in energy conversion learning from baking bread using Joule’s heat. A teaching plan was drawn up to standardize the educational context for student teachers with different backgrounds. Also, a safety guidance was formulated, taking into account the use of high−electric current. Then, laboratory experi...
Atmosphere and Ocean Research Institute, The University of Tokyo, C llege of Art and Design, Musa... more Atmosphere and Ocean Research Institute, The University of Tokyo, C llege of Art and Design, Musashino Art University, Interactive Research Center of Science, Tokyo Institute of Technology, Graduate School of Education, Naruto University of Education,The Center for Academic Resources and Archives, Botanical Gardens, Tohoku University, National Research Institute for Cultural Properties, Nara, Research Institute for Humanity and Nature
Paleoclimatology and paleoceanography Convener:*Kazuyoshi Yamada(School of Human Sciences, Waseda... more Paleoclimatology and paleoceanography Convener:*Kazuyoshi Yamada(School of Human Sciences, Waseda University), Minoru Ikehara(Center for Advanced Marine Core Research, Kochi University), Tomohisa Irino(Faculty of Environmental Earth Science, Hokkaido University), Yusuke Okazaki(Department of Earth and Planetary Sciences, Graduate School of Science, Kyushu University), Ikuko Kitaba(Kobe University Research Center For Inland Seas), Akihisa Kitamura(Institute of Geosciences, Faculty of Science, Shizuoka University), Masaki Sano(Research Institute for Humanity and Nature), Ryuji Tada(Department of Earth and Planetary Science, Graduate School of Science, The Univeristy of Tokyo), Masakazu Yoshimori(Atmosphere and Ocean Research Institute, University of Tokyo), Chair:Masaki Sano(Research Institute for Humanity and Nature) Mon. Apr 28, 2014 11:00 AM 12:45 PM 501 (5F) We discuss past environmental changes and events at multi-decadal to tectonic timescale toward an understanding of Earth cli...
Elemental carbon (EC) is a combustion product which is composed of rich C and depleted O, H, S, N... more Elemental carbon (EC) is a combustion product which is composed of rich C and depleted O, H, S, N. Biomass burning is major source of Pre-industrial EC, while fossil fuel burning has been the most important source since the 18th century. Black carbon (BC) transfered in the atmosphere as aelosols, including EC have a great impact on the climate. EC is also the second strongest contributor to global warming, and has effect to darken snow and ice surface. On the other hand, aerosols including EC have also negative effect on radiative forcing, which lead cooling. Although it is difficult to evaluate the net EC effect on climate, it is necessary to discriminate EC produced by fossil fuel burning from those from biomass burning. EC is not a single chemical compound, but it can be classified into two types , char and soot. Char is produced by pyrolysis, while soot is formed via gas-to-particle conversion. The char particles which are countable under microscope are called charcoal. There ar...
The beginning of agriculture in Ryukyu Islands goes back to the 10th-12th century (Takamiya and I... more The beginning of agriculture in Ryukyu Islands goes back to the 10th-12th century (Takamiya and Itoh, 2011). Land clearing for farm lands accelerated soil discharge into water systems in Ryukyu Islands due to heavy rain in summer. In a closed bay, finer-grained clastics can remain sub-merged for long periods, causing adverse effects in fishery. In this study we will report on the analytical results for sediment cores recovered from Haneji-naikai. Haneji-naikai is a bay closed by the Yagachi and Okubu Islands. Its maximum water depth is 10 m with the area is 10km . The Nasata river flows into the Haneji-naikai. In 2010 and 2012, 3-m and 24-m long sediment cores were recovered from the center of the bay. These were used to reconstruct the past environmental changes and human activities. The latter longer cores consisted of clay and silt with shell fragments from the surface up to the 16-m depth, while he lower part was composed of gravels. The radiocarbon dates of terrestrial plant fl...
Abstract Rebun is a small island located northwest of Hokkaido Island where hunter-fisher-gathere... more Abstract Rebun is a small island located northwest of Hokkaido Island where hunter-fisher-gatherer cultural traditions continued until the 19th century CE. In this study, we quantified polycyclic aromatic hydrocarbons (PAHs), pentacyclic triterpene methyl ethers (PTMEs), n-fatty acids, and glycerol dialkyl glycerol tetraethers (GDGTs) in sediments from Lake Kushu in northern Rebun Island to reconstruct changes in limnology, the local environment and local to regional fire activities during the past 17,000 years (i.e., 17 ka). The PAH concentration increased from 11 to 10 cal ka BP. PAH and PTME compositions indicate that this change was associated with an increase of fire activity at proximal locations (i.e., the vicinity of Lake Kushu) and a change in the composition of grasses growing around the lake. A peak in PAH concentrations at 6.6–6.0 cal ka BP likely indicates intensive fire activity on Rebun Island. The PAH composition after 6 cal ka BP mainly reflected the combustion of conifers near the lake. The GDGTs, n-fatty acids, perylene, and PTME concentrations were higher around 10 cal ka BP and after 6 cal ka BP compared to the remaining periods, suggesting better preservation of those compounds under lake conditions marked by lower oxygen concentrations.
Proceedings of the National Academy of Sciences of the United States of America, Feb 7, 2017
The lowland Maya site of Ceibal, Guatemala, had a long history of occupation, spanning from the M... more The lowland Maya site of Ceibal, Guatemala, had a long history of occupation, spanning from the Middle Preclassic Period through the Terminal Classic (1000 BC to AD 950). The Ceibal-Petexbatun Archaeological Project has been conducting archaeological investigations at this site since 2005 and has obtained 154 radiocarbon dates, which represent the largest collection of radiocarbon assays from a single Maya site. The Bayesian analysis of these dates, combined with a detailed study of ceramics, allowed us to develop a high-precision chronology for Ceibal. Through this chronology, we traced the trajectories of the Preclassic collapse around AD 150-300 and the Classic collapse around AD 800-950, revealing similar patterns in the two cases. Social instability started with the intensification of warfare around 75 BC and AD 735, respectively, followed by the fall of multiple centers across the Maya lowlands around AD 150 and 810. The population of Ceibal persisted for some time in both cas...
Proceedings of the National Academy of Sciences, 2015
Our archaeological investigations at Ceibal, a lowland Maya site located in the Pasión region, do... more Our archaeological investigations at Ceibal, a lowland Maya site located in the Pasión region, documented that a formal ceremonial complex was built around 950 B.C. at the onset of the Middle Preclassic period, when ceramics began to be used in the Maya lowlands. Our refined chronology allowed us to trace the subsequent social changes in a resolution that had not been possible before. Many residents of Ceibal appear to have remained relatively mobile during the following centuries, living in ephemeral post-in-ground structures and frequently changing their residential localities. In other parts of the Pasión region, there may have existed more mobile populations who maintained the traditional lifestyle of the preceramic period. Although the emerging elite of Ceibal began to live in a substantial residential complex by 700 B.C., advanced sedentism with durable residences rebuilt in the same locations and burials placed under house floors was not adopted in most residential areas unti...
ABSTRACT The Kiso-hinoki (Kiso-Japanese cypress, Chamaecyparis obtusa) woodland underwent severe ... more ABSTRACT The Kiso-hinoki (Kiso-Japanese cypress, Chamaecyparis obtusa) woodland underwent severe deforestation in the early 17th century, then regenerated through conservation during the Edo period. Now, a suitable management strategy is sought in order to maintain its ecological function in the forest. To understand the vegetation changes and human impact, sediment cores were recovered from Lake Tadachi in the Kiso-hinoki cypress woodland in the central uphill region of Honshu island. In addition, stratigraphic pollen analysis on two cores (Nos. 6 and 10) and phytolith analysis on three strata of one core (No. 6) was conducted. The age-depth models were constructed based on 14C dating, greyscale analysis on the sediments, and the increasing level of Cryptomeria pollen (about a.d. 1960) from the pollen profiles. In all periods, the dominant pollen taxa were Cupressaceae and Quercus subgen. Lepidobalanus type. Our analysis indicates that after the commencement of Shikinen-sengu, which is the rebuilding of the Ise Grand Shrine every 20 years, Cupressaceae pollen decreased and the woodland was gradually replaced by Quercus subgen. Lepidobalanus. The percentages of Cupressaceae pollen decreased dramatically and the expansion of secondary woodlands was accompanied by an increase of Quercus subgen. Lepidobalanus in the early 17th century cal. a.d. However, depletion of the woodland was determined from a decrease in concentration of Quercus pollen. The conservation activity during the Edo period and after the Meiji Restoration brought about woodland recovery. However, based on our pollen and phytolith analysis, significant changes to the woodland habitats can be detected. These were probably due to human impacts, most notably in the years after World War II. Four major turning points as the result of human influence were identified: the 10th century, the late 16th century, the Meiji restoration (a.d. 1863), and the end of World War II. The original cypress woodland mixed with deciduous broad-leaved elements has been greatly reduced, preventing future cypress woodland regeneration after World War II.
Dating Carbon Radiocarbon dating is the best way to determine the age of samples that contain car... more Dating Carbon Radiocarbon dating is the best way to determine the age of samples that contain carbon and that are younger than ∼50,000 years, the limit of precision for the method. There are several factors that complicate such age determinations, however, some of the most important of which include variability of the 14 C production in the atmosphere (which affects organic samples whose radiocarbon inventories are derived from atmospheric CO 2 ), surface ocean reservoir effects (which affect marine samples that acquire their radiocarbon signatures from seawater), and variable dead carbon fraction effects (which affect speleothems that derive their carbon from groundwaters). Bronk Ramsey et al. (p. 370 ; see the Perspective by Reimer ) avoid the need to make such assumptions, reporting the 14 C results of sediments from Lake Suigetsu, Japan. Analysis of terrestrial plant macrofossils in annually layered datable sediments yielded a direct record of atmospheric radiocarbon for the ent...
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