Effect of Elemental Shape and Modeling of Mixed Hybrid FEM on Numerical Solution

AbstractMixed Hybrid Finite element method, MHF, is known to be an efficient and powerful analyzing technique with satisfactory accuracy when differentiated variables should be evaluated, such as flow velocity based on velocity potential theory or stress calculated from displacement. On the other hand, it is known that the calculation accuracy and efficiency are affected by elemental shape and modeling. The aim of this study is to confirm the efficiency and accuracy of MHF by comparing it with FEM, and to discuss optimum elemental shapes and modeling. MHF, unlike FEM, evaluates the velocity potential and the flux on the element boundaries not at the element nodes; consequently, the material or mass balance of each element due to flow-in and flow-out through the boundaries can be strictly estimated. The flow velocity within an element, however, should be interpolated by those values on the boundaries, and a distinctive shape function, known as the Raviart-Thomas shape function, becomes necessary. The authors established the MHF formulation for arbitrary shaped elements with 3 and 4 boundaries, and numerically investigated its efficiency and accuracy with various shapes of elements. Through this study, it was confirmed that MHF can evaluate accurate flow velocity with a fewer number of elements than those of FEM. In addition, the effect of shape and modeling of elements on the numerical results were discussed to obtain better accuracy even if the total number of the elements is kept constant

Vasopressin gene products are colocalised with corticotrophin‐releasing factor within neurosecretory vesicles in the external zone of the median eminence of the Japanese macaque monkey (Macaca fuscata)

Arginine vasopressin (AVP), when released into portal capillaries with corticotrophin‐releasing factor (CRF) from terminals of parvocellular neurones of the hypothalamic paraventricular nucleus (PVH), facilitates the secretion of adrenocorticotrophic hormone (ACTH) in stressed rodents. The AVP gene encodes a propeptide precursor containing AVP, AVP‐associated neurophysin II (NPII), and a glycopeptide copeptin, although it is currently unclear whether copeptin is always cleaved from the neurophysin and whether the NPII and/or copeptin have any functional role in the pituitary. Furthermore, for primates, it is unknown whether CRF, AVP, NPII and copeptin are all colocalised in neurosecretory vesicles in the terminal region of the paraventricular CRF neurone axons. Therefore, we investigated, by fluorescence and immunogold immunocytochemistry, the cellular and subcellular relationships of these peptides in the CRF‐ and AVP‐producing cells in unstressed Japanese macaque monkeys (Macaca fuscata). Reverse transcription‐polymerase chain reaction analysis showed the expression of both CRF and AVP mRNAs in the monkey PVH. As expected, in the magnocellular neurones of the PVH and supraoptic nucleus, essentially no CRF immunoreactivity could be detected in NPII‐immunoreactive (AVP‐producing) neurones. Immunofluorescence showed that, in the parvocellular part of the PVH, NPII was detectable in a subpopulation (approximately 39%) of the numerous CRF‐immunoreactive neuronal perikarya, whereas, in the outer median eminence, NPII was more prominent (approximately 52%) in the CRF varicosities. Triple immunoelectron microscopy in the median eminence demonstrated the presence of both NPII and copeptin immunoreactivity in dense‐cored vesicles of CRF‐containing axons. The results are consistent with an idea that the AVP propeptide is processed and NPII and copeptin are colocalised in hypothalamic‐pituitary CRF axons in the median eminence of a primate. The CRF, AVP and copeptin are all co‐packaged in neurosecretory vesicles in monkeys and are thus likely to be co‐released into the portal capillary blood to amplify ACTH release from the primate anterior pituitary

Immunoelectron Microscopic Characterization of Vasopressin-Producing Neurons in the Hypothalamo-Pituitary Axis of Non-Human Primates by Use of Formaldehyde-Fixed Tissues Stored at-25 degrees C for Several Years

Translational research often requires the testing of experimental therapies in primates, but research in non-human primates is now stringently controlled by law around the world. Tissues fixed in formaldehyde without glutaraldehyde have been thought to be inappropriate for use in electron microscopic analysis, particularly those of the brain. Here we report the immunoelectron microscopic characterization of arginine vasopressin (AVP)-producing neurons in macaque hypothalamo-pituitary axis tissues fixed by perfusion with 4% formaldehyde and stored at -25 degrees C for several years (4-6 years). The size difference of dense-cored vesicles between magnocellular and parvocellular AVP neurons was detectable in their cell bodies and perivascular nerve endings located, respectively, in the posterior pituitary and median eminence. Furthermore, glutamate and the vesicular glutamate transporter 2 could be colocalized with AVP in perivascular nerve endings of both the posterior pituitary and the external layer of the median eminence, suggesting that both magnocellular and parvocellular AVP neurons are glutamatergic in primates. Both ultrastructure and immunoreactivity can therefore be sufficiently preserved in macaque brain tissues stored long-term, initially for light microscopy. Taken together, these results suggest that this methodology could be applied to the human post-mortem brain and be very useful in translational research

Variation of pro‐vasopressin processing in parvocellular and magnocellular neurons in the paraventricular nucleus of the hypothalamus: Evidence from the vasopressin‐related glycopeptide copeptin

Arginine vasopressin (AVP) is synthesized in parvocellular‐ and magnocellular neuroendocrine neurons in the paraventricular nucleus (PVN) of the hypothalamus. Whereas magnocellular AVP neurons project primarily to the posterior pituitary, parvocellular AVP neurons project to the median eminence (ME) and to extrahypothalamic areas. The AVP gene encodes pre‐pro‐AVP that comprises the signal peptide, AVP, neurophysin (NPII), and a copeptin glycopeptide. In the present study, we used an N‐terminal copeptin antiserum to examine copeptin expression in magnocellular and parvocellular neurons in the hypothalamus in the mouse, rat, and macaque monkey. Although magnocellular NPII‐expressing neurons exhibited strong N‐terminal copeptin immunoreactivity in all three species, a great majority (~90%) of parvocellular neurons that expressed NPII was devoid of copeptin immunoreactivity in the mouse, and in approximately half (~53%) of them in the rat, whereas in monkey hypothalamus, virtually all NPII‐immunoreactive parvocellular neurons contained strong copeptin immunoreactivity. Immunoelectron microscopy in the mouse clearly showed copeptin‐immunoreactivity co‐localized with NPII‐immunoreactivity in neurosecretory vesicles in the internal layer of the ME and posterior pituitary, but not in the external layer of the ME. Intracerebroventricular administration of a prohormone convertase inhibitor, hexa‐d‐arginine amide resulted in a marked reduction of copeptin‐immunoreactivity in the NPII‐immunoreactive magnocellular PVN neurons in the mouse, suggesting that low protease activity and incomplete processing of pro‐AVP could explain the disproportionally low levels of N‐terminal copeptin expression in rodent AVP (NPII)‐expressing parvocellular neurons. Physiologic and phylogenetic aspects of copeptin expression among neuroendocrine neurons require further exploration

Randomized, Phase II Study Comparing Interferon Combined with Hepatic Arterial Infusion of Fluorouracil plus Cisplatin and Fluorouracil Alone in Patients with Advanced Hepatocellular Carcinoma

Objective: This randomized phase II trial compared the response rates to treatment with interferon (IFN) combined with hepatic arterial infusion of fluorouracil (FU) plus cisplatin (CDDP) or FU alone in patients with advanced hepatocellular carcinoma (HCC). Methods: A total of 114 patients with measurable advanced HCC were enrolled and randomized into 2 groups. FU (300 mg/m2, days 1–5, days 8–12) with or without CDDP (20 mg/m2, days 1 and 8) was administered via the hepatic artery. IFNα-2b was administered 3 times per week for 4 weeks. Results: The response rates were 45.6% for the IFN/FU + CDDP group and 24.6% for the IFN/FU group. The response rate was significantly higher in the IFN/FU + CDDP group (p = 0.030). The median overall survival period was 17.6 months in the IFN/FU + CDDP group versus 10.5 months in the IFN/FU group (p = 0.522). The median progression-free survival period was 6.5 months in the IFN/FU + CDDP group versus 3.3 months in the IFN/FU group (p = 0.0048). Hematological toxicity was common, but no toxicity-related deaths were observed. Conclusion: These results show the clinical efficacy of adding CDDP to the hepatic arterial infusion of FU in combined chemotherapy regimens with IFN

Coincidence analysis to search for inspiraling compact binaries using TAMA300 and LISM data

Japanese laser interferometric gravitational wave detectors, TAMA300 and LISM, performed a coincident observation during 2001. We perform a coincidence analysis to search for inspiraling compact binaries. The length of data used for the coincidence analysis is 275 hours when both TAMA300 and LISM detectors are operated simultaneously. TAMA300 and LISM data are analyzed by matched filtering, and candidates for gravitational wave events are obtained. If there is a true gravitational wave signal, it should appear in both data of detectors with consistent waveforms characterized by masses of stars, amplitude of the signal, the coalescence time and so on. We introduce a set of coincidence conditions of the parameters, and search for coincident events. This procedure reduces the number of fake events considerably, by a factor $\sim 10^{-4}$ compared with the number of fake events in single detector analysis. We find that the number of events after imposing the coincidence conditions is consistent with the number of accidental coincidences produced purely by noise. We thus find no evidence of gravitational wave signals. We obtain an upper limit of 0.046 /hours (CL $= 90$) to the Galactic event rate within 1kpc from the Earth. The method used in this paper can be applied straightforwardly to the case of coincidence observations with more than two detectors with arbitrary arm directions.Comment: 28 pages, 17 figures, Replaced with the version to be published in Physical Review

Results of the search for inspiraling compact star binaries from TAMA300's observation in 2000-2004

We analyze the data of TAMA300 detector to search for gravitational waves from inspiraling compact star binaries with masses of the component stars in the range 1-3Msolar. In this analysis, 2705 hours of data, taken during the years 2000-2004, are used for the event search. We combine the results of different observation runs, and obtained a single upper limit on the rate of the coalescence of compact binaries in our Galaxy of 20 per year at a 90% confidence level. In this upper limit, the effect of various systematic errors such like the uncertainty of the background estimation and the calibration of the detector's sensitivity are included.Comment: 8 pages, 4 Postscript figures, uses revtex4.sty The author list was correcte

DECIGO pathfinder

DECIGO pathfinder (DPF) is a milestone satellite mission for DECIGO (DECi-hertz Interferometer Gravitational wave Observatory) which is a future space gravitational wave antenna. DECIGO is expected to provide us fruitful insights into the universe, in particular about dark energy, a formation mechanism of supermassive black holes, and the inflation of the universe. Since DECIGO will be an extremely large mission which will formed by three drag-free spacecraft with 1000m separation, it is significant to gain the technical feasibility of DECIGO before its planned launch in 2024. Thus, we are planning to launch two milestone missions: DPF and pre-DECIGO. The conceptual design and current status of the first milestone mission, DPF, are reviewed in this article

The Japanese space gravitational wave antenna; DECIGO

DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future Japanese space gravitational wave antenna. DECIGO is expected to open a new window of observation for gravitational wave astronomy especially between 0.1 Hz and 10 Hz, revealing various mysteries of the universe such as dark energy, formation mechanism of supermassive black holes, and inflation of the universe. The pre-conceptual design of DECIGO consists of three drag-free spacecraft, whose relative displacements are measured by a differential Fabry– Perot Michelson interferometer. We plan to launch two missions, DECIGO pathfinder and pre- DECIGO first and finally DECIGO in 2024

Observation results by the TAMA300 detector on gravitational wave bursts from stellar-core collapses

We present data-analysis schemes and results of observations with the TAMA300 gravitational-wave detector, targeting burst signals from stellar-core collapse events. In analyses for burst gravitational waves, the detection and fake-reduction schemes are different from well-investigated ones for a chirp-wave analysis, because precise waveform templates are not available. We used an excess-power filter for the extraction of gravitational-wave candidates, and developed two methods for the reduction of fake events caused by non-stationary noises of the detector. These analysis schemes were applied to real data from the TAMA300 interferometric gravitational wave detector. As a result, fake events were reduced by a factor of about 1000 in the best cases. The resultant event candidates were interpreted from an astronomical viewpoint. We set an upper limit of 2.2x10^3 events/sec on the burst gravitational-wave event rate in our Galaxy with a confidence level of 90%. This work sets a milestone and prospects on the search for burst gravitational waves, by establishing an analysis scheme for the observation data from an interferometric gravitational wave detector