TY  - JOUR
A1  - Le Friant, A.
A1  - Ishizuka, O.
A1  - Boudon, G.
A1  - Palmer, M. R.
A1  - Talling, P. J.
A1  - Villemant, B.
A1  - Adachi, T.
A1  - Aljahdali, M.
A1  - Breitkreuz, C.
A1  - Brunet, M.
A1  - Caron, B.
A1  - Coussens, M.
A1  - Deplus, C.
A1  - Endo, D.
A1  - Feuillet, N.
A1  - Fraas, A. J.
A1  - Fujinawa, A.
A1  - Hart, M. B.
A1  - Hatfield, R. G.
A1  - Hornbach, M.
A1  - Jutzeler, M.
A1  - Kataoka, K. S.
A1  - Komorowski, J. -C.
A1  - Lebas, E.
A1  - Lafuerza, S.
A1  - Maeno, F.
A1  - Manga, M.
A1  - Martinez-Colon, M.
A1  - McCanta, M.
A1  - Morgan, S.
A1  - Saito, T.
A1  - Slagle, A.
A1  - Sparks, S.
A1  - Stinton, A.
A1  - Stroncik, Nicole
A1  - Subramanyam, K. S. V.
A1  - Tamura, Yui
A1  - Trofimovs, J.
A1  - Voight, B.
A1  - Wall-Palmer, D.
A1  - Wang, F.
A1  - Watt, S. F. L.
T1  - Submarine record of volcanic island construction and collapse in the Lesser Antilles arc: First scientific drilling of submarine volcanic island landslides by IODP Expedition 340
JF  - Geochemistry, geophysics, geosystems
N2  - IODP Expedition 340 successfully drilled a series of sites offshore Montserrat, Martinique and Dominica in the Lesser Antilles from March to April 2012. These are among the few drill sites gathered around volcanic islands, and the first scientific drilling of large and likely tsunamigenic volcanic island-arc landslide deposits. These cores provide evidence and tests of previous hypotheses for the composition and origin of those deposits. Sites U1394, U1399, and U1400 that penetrated landslide deposits recovered exclusively seafloor sediment, comprising mainly turbidites and hemipelagic deposits, and lacked debris avalanche deposits. This supports the concepts that i/ volcanic debris avalanches tend to stop at the slope break, and ii/ widespread and voluminous failures of preexisting low-gradient seafloor sediment can be triggered by initial emplacement of material from the volcano. Offshore Martinique (U1399 and 1400), the landslide deposits comprised blocks of parallel strata that were tilted or microfaulted, sometimes separated by intervals of homogenized sediment (intense shearing), while Site U1394 offshore Montserrat penetrated a flat-lying block of intact strata. The most likely mechanism for generating these large-scale seafloor sediment failures appears to be propagation of a decollement from proximal areas loaded and incised by a volcanic debris avalanche. These results have implications for the magnitude of tsunami generation. Under some conditions, volcanic island landslide deposits composed of mainly seafloor sediment will tend to form smaller magnitude tsunamis than equivalent volumes of subaerial block-rich mass flows rapidly entering water. Expedition 340 also successfully drilled sites to access the undisturbed record of eruption fallout layers intercalated with marine sediment which provide an outstanding high-resolution data set to analyze eruption and landslides cycles, improve understanding of magmatic evolution as well as offshore sedimentation processes.
KW  - landslide
KW  - volcanic island
KW  - debris avalanche
KW  - seafloor sediment failure
KW  - tsunami
KW  - IODP
Y1  - 2015
U6  - https://doi.org/10.1002/2014GC005652
SN  - 1525-2027
VL  - 16
IS  - 2
SP  - 420
EP  - 442
PB  - American Geophysical Union
CY  - Washington
ER  - 
TY  - JOUR
A1  - Tran, V. Phuong
A1  - Tamura, Yui
A1  - Pham, Van-Cuong
A1  - Elhussiny, Mohamed Z.
A1  - Han, Guofeng
A1  - Sur Chowdhury, Vishwajit
A1  - Furuse, Mitsuhiro
T1  - Neuropeptide Y modifies a part of diencephalic catecholamine but not indolamine metabolism in chicks depending on feeding status
JF  - Neuropeptides
N2  - The role of the monoaminergic system in the feeding behavior of neonatal chicks has been reported, but the functional relationship between the metabolism of monoamines and appetite-related neuropeptides is still unclear. This study aimed to investigate the changes in catecholamine and indolamine metabolism in response to the central action of neuropeptide Y (NPY) in different feeding statuses and the underlying mechanisms. In Experiment 1, the diencephalic concentrations of amino acids and monoamines following the intracerebroventricular (ICV) injection of NPY (375 pmol/10 mu l/chick), saline solution under ad libitum, and fasting conditions for 30 min were determined. Central NPY significantly decreased L-tyrosine concentration, the precursor of catecholamines under feeding condition, but not under fasting condition. Central NPY significantly increased dopamine metabolites, including 3,4-dihydroxyphenylacetic acid and homovanillic acid (HVA). The concentration of 3-methoxy-4-hydroxyphenylglycol was significantly reduced under feeding condition, but did not change under fasting condition by NPY. However, no effects of NPY on indolamine metabolism were found in either feeding status. Therefore, the mechanism of action of catecholamines with central NPY under feeding condition was elucidated in Experiment 2. Central NPY significantly attenuated diencephalic gene expression of catecholaminergic synthetic enzymes, such as tyrosine hydroxylase, L-aromatic amino acid decarboxylase, and GTP cyclohydrolase I after 30 min of feeding. In Experiment 3, co-injection of alpha-methyl-L-tyrosine, an inhibitor of tyrosine hydroxylase with NPY, moderately attenuated the orexigenic effect of NPY, accompanied by a significant positive correlation between food intake and HVA levels. In Experiment 4, there was a significant interaction between NPY and clorgyline, an inhibitor of monoamine oxidase A with ICV co-injection which implies that co-existence of NPY and clorgyline enhances the orexigenic effect of NPY. In conclusion, central NPY modifies a part of catecholamine metabolism, which is illustrated by the involvement of dopamine transmission and metabolism under feeding but not fasting conditions.
KW  - Neuropeptide Y
KW  - Feeding behavior
KW  - Neonatal chick
KW  - CNS
KW  - Catecholamines
Y1  - 2021
U6  - https://doi.org/10.1016/j.npep.2021.102169
SN  - 0143-4179
SN  - 1532-2785
VL  - 89
PB  - Elsevier
CY  - New York, NY
ER  -