Axisymmetric general relativistic hydrodynamics: Long-term evolution of neutron stars and stellar collapse to neutron stars and black holes

We report a new implementation for axisymmetric simulation in full general relativity. In this implementation, the Einstein equations are solved using the Nakamura-Shibata formulation with the so-called cartoon method to impose an axisymmetric boundary condition, and the general relativistic hydrodynamic equations are solved using a high-resolution shock-capturing scheme based on an approximate Riemann solver. As tests, we performed the following simulations: (i) long-term evolution of non-rotating and rapidly rotating neutron stars, (ii) long-term evolution of neutron stars of a high-amplitude damping oscillation accompanied with shock formation, (iii) collapse of unstable neutron stars to black holes, and (iv) stellar collapses to neutron stars. The tests (i)--(iii) were carried out with the $\Gamma$-law equation of state, and the test (iv) with a more realistic parametric equation of state for high-density matter. We found that this new implementation works very well: It is possible to perform the simulations for stable neutron stars for more than 10 dynamical time scales, to capture strong shocks formed at stellar core collapses, and to accurately compute the mass of black holes formed after the collapse and subsequent accretion. In conclusion, this implementation is robust enough to apply to astrophysical problems such as stellar core collapse of massive stars to a neutron star and black hole, phase transition of a neutron star to a high-density star, and accretion-induced collapse of a neutron star to a black hole. The result for the first simulation of stellar core collapse to a neutron star started from a realistic initial condition is also presented.Comment: 28 pages, to appear in PRD 67, 0440XX (2003

First Simultaneous Observation of H-alpha Moreton Wave, EUV Wave, and Filament/Prominence Oscillations

We report on the first simultaneous observation of an H-alpha Moreton wave, the corresponding EUV fast coronal waves, and a slow and bright EUV wave (typical EIT wave). Associated with an X6.9 flare that occurred on 2011 August 9 at the active region NOAA 11263, we observed a Moreton wave in the H-alpha images taken by the Solar Magnetic Activity Research Telescope (SMART) at Hida Observatory of Kyoto University. In the EUV images obtained by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamic Observatory (SDO) we found not only the corresponding EUV fast "bright" coronal wave, but also the EUV fast "faint" wave that is not associated with the H-alpha Moreton wave. We also found a slow EUV wave, which corresponds to a typical EIT wave. Furthermore, we observed, for the first time, the oscillations of a prominence and a filament, simultaneously, both in the H-alpha and EUV images. To trigger the oscillations by the flare-associated coronal disturbance, we expect a coronal wave as fast as the fast-mode MHD wave with the velocity of about 570 - 800 km/s. These velocities are consistent with those of the observed Moreton wave and the EUV fast coronal wave.Comment: 15 pages, 5 figures, accepted for publication in ApJ

Raloxifene inhibits tumor growth and lymph node metastasis in a xenograft model of metastatic mammary cancer

<p>Abstract</p> <p>Background</p> <p>The effects of raloxifene, a novel selective estrogen receptor modulator, were studied in a mouse metastatic mammary cancer model expressing cytoplasmic ERα.</p> <p>Methods</p> <p>Mammary tumors, induced by inoculation of syngeneic BALB/c mice with BJMC3879luc2 cells, were subsequently treated with raloxifene at 0, 18 and 27 mg/kg/day using mini-osmotic pumps.</p> <p>Results</p> <p><it>In vitro </it>study demonstrated that the ERα in BJMC3879luc2 cells was smaller (between 50 and 64 kDa) than the normal-sized ERα (66 kDa) and showed cytoplasmic localization. A statistically significant but weak estradiol response was observed in this cell line. When BJMC3879luc2 tumors were implanted into mice, the ERα mRNA levels were significantly higher in females than in males. <it>In vitro </it>studies showed that raloxifene induced mitochondria-mediated apoptosis and cell-cycle arrest in the G1-phase and a decrease in the cell population in the S-phase. In animal experiments, tumor volumes were significantly suppressed in the raloxifene-treated groups. The multiplicity of lymph node metastasis was significantly decreased in the 27 mg/kg group. Levels of apoptosis were significantly increased in the raloxifene-treated groups, whereas the levels of DNA synthesis were significantly decreased in these groups. No differences in microvessel density in tumors were observed between the control and raloxifene-treated groups. The numbers of dilated lymphatic vessels containing intraluminal tumor cells were significantly reduced in mammary tumors in the raloxifene-treated groups. The levels of ERα mRNA in mammary tumors tended to be decreased in the raloxifene-treated groups.</p> <p>Conclusion</p> <p>These results suggest that the antimetastatic activity of raloxifene in mammary cancer expressing cytoplasmic ERα may be a crucial finding with clinical applications and that raloxifene may be useful as an adjuvant therapy and for the chemoprevention of breast cancer development.</p

α-Mangostin extracted from the pericarp of the mangosteen (Garcinia mangostana Linn) reduces tumor growth and lymph node metastasis in an immunocompetent xenograft model of metastatic mammary cancer carrying a p53 mutation

<p>Abstract</p> <p>Background</p> <p>The mangosteen fruit has a long history of medicinal use in Chinese and Ayurvedic medicine. Recently, the compound α-mangostin, which is isolated from the pericarp of the fruit, was shown to induce cell death in various types of cancer cells in <it>in vitro </it>studies. This led us to investigate the antitumor growth and antimetastatic activities of α-mangostin in an immunocompetent xenograft model of mouse metastatic mammary cancer having a p53 mutation that induces a metastatic spectrum similar to that seen in human breast cancers.</p> <p>Methods</p> <p>Mammary tumors, induced by inoculation of BALB/c mice syngeneic with metastatic BJMC3879luc2 cells, were subsequently treated with α-mangostin at 0, 10 and 20 mg/kg/day using mini-osmotic pumps and histopathologically examined. To investigate the mechanisms of antitumor ability by α-mangostin, <it>in vitro </it>studies were also conducted.</p> <p>Results</p> <p>Not only were <it>in vivo </it>survival rates significantly higher in the 20 mg/kg/day α-mangostin group versus controls, but both tumor volume and the multiplicity of lymph node metastases were significantly suppressed. Apoptotic levels were significantly increased in the mammary tumors of mice receiving 20 mg/kg/day and were associated with increased expression of active caspase-3 and -9. Other significant effects noted at this dose level were decreased microvessel density and lower numbers of dilated lymphatic vessels containing intraluminal tumor cells in mammary carcinoma tissues.</p> <p><it>In vitro</it>, α-mangostin induced mitochondria-mediated apoptosis and G1-phase arrest and S-phase suppression in the cell cycle. Since activation by Akt phosphorylation plays a central role in a variety of oncogenic processes, including cell proliferation, anti-apoptotic cell death, angiogenesis and metastasis, we also investigated alterations in Akt phosphorylation induced by α-mangostin treatment both <it>in vitro </it>and <it>in vivo</it>. Quantitative analysis and immunohistochemistry showed that α-mangostin significantly decreased the levels of phospho-Akt-threonine 308 (Thr308), but not serine 473 (Ser473), in both mammary carcinoma cell cultures and mammary carcinoma tissues <it>in vivo</it>.</p> <p>Conclusions</p> <p>Since lymph node involvement is the most important prognostic factor in breast cancer patients, the antimetastatic activity of α-mangostin as detected in mammary cancers carrying a p53 mutation in the present study may have specific clinical applications. In addition, α-mangostin may have chemopreventive benefits and/or prove useful as an adjuvant therapy, or as a complementary alternative medicine in the treatment of breast cancer.</p

Interactions between CKD and MetS and the Development of CVD

Metabolic syndrome (MetS) consists of a combination of metabolic disorders, including increased abdominal circumference, hyperglycemia, elevated blood pressure, and lipid disorders. MetS is now widely accepted as a crucial risk factor for the development of cardiovascular disease (CVD) and mortality. In addition, persistent proteinuria indicating chronic kidney disease (CKD) is well known as a powerful risk factor for the progression of end-stage renal disease and CVD. In recent years, patients with CKD and MetS appear to be increasing along with increasing incidence of CVD in industrial countries

SEED ABORTION IN NATURALLY POLLINATED FLOWERS OF MEXICAN NATIVE PLANTS OF \u3ci\u3ePhaseolus coccineus\u3c/i\u3e L.

INTRODUCTION: Phaseolus coccineus L. plants require insects or hummingbirds to pollinate their flowers and set pods. The number of pods that can be produced by a plant is set by the number of flowers while the number of seeds is set by the number of ovules within the flowers (Stephenson, 1981). The arrest of the development of the seed after its partial differentiation, - seed abortion-, also determines the number of seeds per plant. The objective of this work is to determine the percentage of seed abortion per plant of two Mexican native varieties of Phaseolus coccineus L. MATERIALS AND METHODS: Two varieties (accessions no. 8446 and 8448) were selected from the Mexican bean collection of the Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP). Seeds harvested in November 2014, were sown in pots on April 5, 2015 and seedlings were transplanted outdoors on April 20, distant 2 meter apart. The plants were of indeterminate growth, climbing type. There were a natural occurrence of bees, bumblebees, and hummingbirds pollinators during the flowering period. The experiment was a complete randomized design, with two treatments (varieties), five replications (one plant per replication) and five sampling dates (Oct. 14, Nov. 4, Nov. 25, Dec. 9, and Dec. 16). At each sampling date, the mature pods per plant were harvested and opened. The following data were registered: a) the number of normal seeds per pod; b) the number of aborted seeds per pod including early abortions detected with the stereoscopic microscope. The sum of (a) and (b) = c, which represented the potential number of seeds per POD in each sampling date. It was evident at this point that practically all the pods in a variety had the same potential number of seeds. Therefore, the potential number of seeds per PLANT in each sampling date represented by Y = c*n, where n represents the number of pods per plant in each sampling date. Following when applicable, the similar procedure for seed abortion: Z = total number of aborted seeds per plant in each sampling date. The percentage of seed abortion (Z/Y)*100 (total number of aborted seeds per plant in each sampling date/potential number of seeds per plant in each sampling date)

SEED ABORTION IN NATURALLY POLLINATED FLOWERS OF MEXICAN NATIVE PLANTS OF \u3ci\u3ePhaseolus coccineus\u3c/i\u3e L.

INTRODUCTION: Phaseolus coccineus L. plants require insects or hummingbirds to pollinate their flowers and set pods. The number of pods that can be produced by a plant is set by the number of flowers while the number of seeds is set by the number of ovules within the flowers (Stephenson, 1981). The arrest of the development of the seed after its partial differentiation, - seed abortion-, also determines the number of seeds per plant. The objective of this work is to determine the percentage of seed abortion per plant of two Mexican native varieties of Phaseolus coccineus L. MATERIALS AND METHODS: Two varieties (accessions no. 8446 and 8448) were selected from the Mexican bean collection of the Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP). Seeds harvested in November 2014, were sown in pots on April 5, 2015 and seedlings were transplanted outdoors on April 20, distant 2 meter apart. The plants were of indeterminate growth, climbing type. There were a natural occurrence of bees, bumblebees, and hummingbirds pollinators during the flowering period. The experiment was a complete randomized design, with two treatments (varieties), five replications (one plant per replication) and five sampling dates (Oct. 14, Nov. 4, Nov. 25, Dec. 9, and Dec. 16). At each sampling date, the mature pods per plant were harvested and opened. The following data were registered: a) the number of normal seeds per pod; b) the number of aborted seeds per pod including early abortions detected with the stereoscopic microscope. The sum of (a) and (b) = c, which represented the potential number of seeds per POD in each sampling date. It was evident at this point that practically all the pods in a variety had the same potential number of seeds. Therefore, the potential number of seeds per PLANT in each sampling date represented by Y = c*n, where n represents the number of pods per plant in each sampling date. Following when applicable, the similar procedure for seed abortion: Z = total number of aborted seeds per plant in each sampling date. The percentage of seed abortion (Z/Y)*100 (total number of aborted seeds per plant in each sampling date/potential number of seeds per plant in each sampling date)

Migraine aura: retracting particle-like waves in weakly susceptible cortex

Cortical spreading depression (SD) has been suggested to underlie migraine aura. Despite a precise match in speed, the spatio-temporal patterns of SD and aura symptoms on the cortical surface ordinarily differ in aspects of size and shape. We show that this mismatch is reconciled by utilizing that both pattern types bifurcate from an instability point of generic reaction-diffusion models. To classify these spatio-temporal pattern we suggest a susceptibility scale having the value [sigma]=1 at the instability point. We predict that human cortex is only weakly susceptible to SD ([sigma]&#x3c;1), and support this prediction by directly matching visual aura symptoms with anatomical landmarks using fMRI retinotopic mapping. We discuss the increased dynamical repertoire of cortical tissue close to [sigma]=1, in particular, the resulting implications on migraine pharmacology that is hitherto tested in the regime ([sigma]&#x3e;&#x3e;1), and potentially silent aura occurring below a second bifurcation point at [sigma]=0 on the susceptible scale

Optical fibers with interferometric path length stability by controlled heating for transmission of optical signals and as components in frequency standards

We present a simple method to stabilize the optical path length of an optical fiber to an accuracy of about 1/100 of the laser wavelength. We study the dynamic response of the path length to modulation of an electrically conductive heater layer of the fiber. The path length is measured against the laser wavelength by use of the Pound-Drever-Hall method; negative feedback is applied via the heater. We apply the method in the context of a cryogenic resonator frequency standard.Comment: Expanded introduction and outlook. 9 pages, 5 figure