Subaru Telescope Observations of Deep Impact

The impact cratering process on a comet is controversial but holds the key for interpreting observations of the Deep Impact collision with comet 9P/Tempel 1. Mid-infrared data from the Cooled Mid-Infrared Camera and Spectrometer (COMICS) of the Subaru Telescope indicate that the large-scale dust plume ejected by the impact contained a large mass (approximately 10(6) kilograms) of dust and formed two wings approximately +/-45 degrees from the symmetric center, both consistent with gravity as the primary control on the impact and its immediate aftermath. The dust distribution in the inner part of the plume, however, is inconsistent with a pure gravity control and implies that evaporation and expansion of volatiles accelerated dust.

Deep Impact: observations from a worldwide Earth-based campaign

On 4 July 2005, many observatories around the world and in space observed the collision of Deep Impact with comet 9P/Tempel 1 or its aftermath. This was an unprecedented coordinated observational campaign. These data show that (i) there was new material after impact that was compositionally different from that seen before impact; (ii) the ratio of dust mass to gas mass in the ejecta was much larger than before impact; (iii) the new activity did not last more than a few days, and by 9 July the comet's behavior was indistinguishable from its pre-impact behavior; and (iv) there were interesting transient phenomena that may be correlated with cratering physics.

Strong Green Emission from α-SiAlON Activated by Divalent Ytterbium under Blue Light Irradiation

This contribution reports on luminescence properties of divalent ytterbium in alpha-SiAlON at room temperature. Ytterbium-doped alpha-SiAlON powders, with the compositions of (M(1-2x/v)Yb(x))(m/v)Si(12-m-n)Al(m+n)O(n)N(16-n) (M = Ca, Li, Mg, and Y, v is the valency of M, 0.002 < or = x < or = 0.10, 0.5 < or = m = 2n < or = 3.5), were synthesized by sintering at 1700 degrees C for 2 h under 0.5 MPa N2. A single, intense, broad emission band, centered at 549 nm, is observed due to the electronic transitions from the excited state 4f(13)5d to the ground state 4f14 of Yb2+. The luminescence of Yb2+ in alpha-SiAlON occurs at relatively low energy, which is attributable to the large crystal field splitting and nephelauxetic effect due to the nitrogen-rich coordination of Yb2+. The dependence of luminescence properties on the Yb2+ concentration, chemical composition, and annealing is discussed. It is suggested that this novel green phosphor could be applied in white light-emitting diodes (LEDs) when combined with a red phosphor and a blue LED.

Behavior and reproductive performance by stalled breeding females on a commercial swine farm

The behavior of stalled females pigs was observed to investigate the relations between behavior and reproductive performance. A commercial farrow-to-finish farm equipped with a computerized recording system with approximately 300 female pig inventories was visited three times to observe three postural behaviors (lying, standing, and sitting) and three stereotypies (vacuum chewing, drinker playing, and bar biting) of stalled females at 15-min intervals for 6 h (25 times including 0 min of one zero-time sampling) after feeding. Relative frequencies (%) of the postural behaviors and the stereotypies for 6 h were expressed as a percentage of a total of 25 time observations. Statistical models for reproductive performance included each behavior, parity, and day of visit. Among 609 pregnant females observed at our three visits, the means in relative frequencies (%) of lying, standing, sitting, vacuum chewing, drinker playing, and bar biting for 6 h were 60.1 +/- 0.91, 32.3 +/- 0.87, 7.60 +/- 0.44, 12.7 +/- 0.65, 0.4 +/- 0.06, and 0.2 +/- 0.50%, respectively. Among 514 farrowed females of the 609 pregnant females, the means of total pigs born, pigs born alive, pigs born dead, birth litter weights, pigs weaned, and adjusted 21-d litter weights were 12.3 +/- 0.13, 11.2 +/- 0.12, 1.1 +/- 0.06, 17.1 +/- 0.18 kg, 10.3 +/- 0.08, and 68.1 +/- 0.40 kg, respectively. Females showing a high relative frequency (> or = 36%) of vacuum chewing during gestation produced fewer (P < 0.05) total pigs born (11.7 +/- 0.38 vs. 12.6 +/- 0.22) than those showing no vacuum chewing. No relationships were found between vacuum chewing and other performance measurements such as pigs born alive, pigs weaned, and adjusted 21-d litter weights. Neither postural behavior nor the other stereotypies were related to reproductive performance. The farrowing rate was not related to any postural behavior and stereotypy in logistic regression mixed models. This study suggests that a subpopulation of females exists on commercial farms that frequently exhibit vacuum chewing and give birth to fewer total pigs. High frequency of vacuum chewing in those females may be indicative of their suboptimal reproductive performance.

Search for Low-Mass Exoplanets by Gravitational Microlensing at High Magnification

Observations of the gravitational microlensing event MOA 2003-BLG-32/OGLE 2003-BLG-219 are presented, for which the peak magnification was over 500, the highest yet reported. Continuous observations around the peak enabled a sensitive search for planets orbiting the lens star. No planets were detected. Planets 1.3 times heavier than Earth were excluded from more than 50% of the projected annular region from approximately 2.3 to 3.6 astronomical units surrounding the lens star, Uranus-mass planets were excluded from 0.9 to 8.7 astronomical units, and planets 1.3 times heavier than Saturn were excluded from 0.2 to 60 astronomical units. These are the largest regions of sensitivity yet achieved in searches for extrasolar planets orbiting any star.

Expression of epiregulin and amphiregulin in the rat ovary

We have previously reported that the epidermal growth factor (EGF) family growth factor, epiregulin, is expressed in rat ovarian granulosa cells by induction with pregnant mare serum gonadotropin (PMSG). In this study, we report that amphiregulin, another member of the EGF family, was also induced in the rat ovary by gonadotropin treatment. Northern blot analysis revealed that PMSG treatment induced the expression of both epiregulin and amphiregulin mRNA after 24 h, but the expression then decreased 48 h after treatment. Further treatment with human chorionic gonadotropin (hCG) rapidly induced the expression of both epiregulin and amphiregulin genes and maximal levels were reached 4 h after hCG treatment. A marginal increase in amphiregulin mRNA levels was also observed 6 h after PMSG treatment. In situ hybridization revealed that epiregulin and amphiregulin mRNAs were localized in the granulosa cells of large antral follicles. These spatio-temporal expression patterns were similar to those of cyclo-oxygenase-2 (COX-2) and progesterone receptor (PR). In adult cycling rats, epiregulin and amphiregulin were strongly induced at 1800 and 2000 h on proestrus coinciding with the preovulatory LH surge. An in situ hybridization study also showed that epiregulin and amphiregulin mRNAs were detectable in the granulosa cells of preovulatory ovarian follicles at 2000 h on proestrus, where transcripts of COX-2 and PR were co-localized with those of epiregulin and amphiregulin. These observations suggested that the EGF family members, epiregulin and amphiregulin, may play a role in the ovulatory process of cycling rats as well as in the induction of ovulation in immature rats.

Improved measurement of the K+-->pi+nunu; branching ratio

An additional event near the upper kinematic limit for K+-->pi(+)nunu; has been observed by experiment E949 at Brookhaven National Laboratory. Combining previously reported and new data, the branching ratio is B(K+-->pi(+)nunu;)=(1.47(+1.30)(-0.89))x10(-10) based on three events observed in the pion momentum region 211<P<229 MeV/c. At the measured central value of the branching ratio, the additional event had a signal-to-background ratio of 0.9.

Preliminary findings of chromosomal alterations and expression of cell cycle genes in head an neck tumors

The genesis and progression of malignant tumors may be related to certain somatic mutations and the accumulation of multiple chromosomal alterations. Using four freshly resected malignant tumors, we investigated the relationship between chromosomal alteration and expression of cell cycle regulatory genes. Specimens of thyroid hyperplasia and normal thyroid tissue were also investigated. As cell cycle regulating genes, we chose the cdc2 gene that encodes the p34cdc2 protein kinase, a major kinase of the cell cycle, and the RCC1 gene that is essential for coupling between S and M phases. Three of the malignant tumors contained cells with chromosomal alterations, including one polyploid and two aneuploid. The DNA content of cells in thyroid hyperplasia was the same as in the normal gland. The amount of p34cdc2 protein was very low in cells of both normal thyroid and hyperplastic tissue, and grew very slowly as compared with malignant tumors. There was no significant relationship between the amount of RCC1 and ploidy pattern.

Inhibition of progression of heart failure and expression of TGF-beta 1 mRNA in rats with heart failure by the ACE inhibitor quinapril

The cardioprotective effects of quinapril, an angiotensin-converting enzyme inhibitor, were studied in a rat model of heart failure. Twenty-six rats were divided into two groups: one given 20 mg/kg/day quinapril (n = 11), and controls given 0.5% methylcellulose (n = 15). After oral administration for 1 month, quinapril reduced heart weight (from 1.28+/-0.05 to 0.87+/-0.02 g; p < 0.05) without changing body weight. Quinapril lowered left ventricular end-diastolic pressure (from 14.1+/-2.0 to 6.6+/-1.5 mmHg; p < 0.05) and central venous pressure (from 2.7+/-0.9 to 0.7+/-0.4 mmHg), and increased +/- dP/dt (from +2409+/-50 to +3569+/-169 mmHg/s, and from -2318+/-235 to -3960+/-203 mmHg/s; both p < 0.01). The area of myocardial fibrosis was markedly reduced by quinapril (6+/-3%) as compared with controls (29+/-6%; p < 0.01). Expression of transforming growth factor (TGF)-beta1 mRNA was markedly increased in controls as compared with age-matched normal rats. The increase in level of TGF-beta1 mRNA was significantly suppressed by quinapril (from 17.1+/-6.2 to 9.00+/-2.40; p < 0.05). These observations indicated that quinapril has cardioprotective effects on heart failure, and that the beneficial effects may be partly explained by attenuation of fibrotic response through suppression of TGF-beta1 mRNA expression.

Oncostatin M suppresses generation of lymphoid progenitors in fetal liver by inhibiting the hepatic microenvironment

OBJECTIVE

Interaction between hematopoietic cells and stromal cells is important for regulation of hematopoiesis. Numerous soluble and membrane-bound factors directly regulating hematopoiesis have been documented, but little is known about how stromal cell activity is controlled. We previously reported that fetal hepatic cells in primary culture create the hematopoietic microenvironment and support expansion of blood cells from hematopoietic stem cells. In this study, we focused on lymphopoiesis reconstituted in our culture system and analyzed how stroma-mediated lymphopoiesis is regulated during embryonic development.

MATERIALS AND METHODS

Subconfluent cultures of murine fetal hepatic cells were cocultured with hematopoietic stem cells derived from fetal liver in the presence of various cytokines. After 10 days of incubation, hematopoietic cells floating over the stromal layer were analyzed by various assays, including cell proliferation and FACS analysis.

RESULTS

We found that oncostatin M, an inducer of hepatic development, strongly inhibited generation of B220(+) lymphocytic cells and colony-forming unit-interleukin-7 (CFU-IL-7) from hematopoietic stem cells in our coculture system. In contrast, oncostatin M did not directly inhibit proliferation of B cells in response to IL-7 and SCF in semisolid cultures. Analysis of antigen expression in lymphoid cells revealed that oncostatin M apparently did not arrest cells at a particular stage of B-cell development.

CONCLUSIONS

The results suggest that oncostatin M inhibits lymphopoiesis by suppressing stromal activity of fetal hepatic cells to stimulate generation of CFU-IL-7 from their progenitors rather than by acting directly on lymphocytic cells.

Molecular cloning of natriuretic peptide receptor A from bullfrog (Rana catesbeiana) brain and its functional expression

A comparative study of natriuretic peptide receptor (NPR) was performed by cloning the NPR-A receptor subtype from the bullfrog (Rana catesbeiana) brain and analyzing its functional expression. Like other mammalian NPR-A receptors, the bullfrog NPR-A receptor consists of an extracellular ligand binding domain, a hydrophobic transmembrane domain, a kinase-like domain and a guanylate cyclase domain. Sequence comparison among the bullfrog and mammalian receptors revealed a relatively low ( approximately 45%) similarity in the extracellular domain compared to a very high similarity ( approximately 92%) in the cytoplasmic regulatory and catalytic domains. Expression of NPR-A mRNA was detected in various bullfrog tissues including the brain, heart, lung, kidney and liver; highest levels were observed in lung. Functional expression of the receptor in COS-7 cells revealed that frog atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) elicited cyclic guanosine 3'5'-monophosphate production by stimulating the receptor in a dose-dependent manner from 10(-10) M concentrations. Rat ANP was also effective in stimulating the frog receptor whereas rat BNP and porcine BNP were less responsive to the receptor. On the other hand, frog C-type natriuretic peptide (CNP) as well as porcine CNP stimulated the receptor only at high concentrations (10(-7) M). This clearly indicates that the bullfrog receptor is a counterpart of mammalian NPR-A, and is specific for ANP or BNP but not for CNP.

The effect of stimulus repetition on cortical magnetic responses evoked by words and nonwords

Stimulus repetition improves performance and modulates event-related brain potentials in word recognition tasks. We recorded evoked magnetic responses from bilateral temporal sites of the brain to determine the cortical area related to the word repetition effect. Fourteen Japanese volunteers read words or pronounceable nonwords, some of which occurred twice with a lag of eight items. Clear magnetic responses were observed bilaterally. In the left hemisphere, a reduction of the magnetic responses by repetition was observed for words but not for nonwords in the latency range of 300-500 ms poststimulus. The sources of the responses were estimated to be in the left perisylvian area adjacent to the auditory cortex and the left parietal area. Only the perisylvian source activity showed the reduction by the word repetition. The left perisylvian area was thus suggested to be related to the word repetition effect. The activity in this area might be associated with the lexical memory process.

Cloning and functional expression of an E box-binding protein from rat granulosa cells

Ovarian granulosa cells undergo cell growth and cytodifferentiation during follicular maturation. In a number of tissues, the gene expression that is responsible for the cytodifferentiation is largely dependent on E box(es) located upstream of the responsible genes. In this study, we report on the cloning of cDNA(s) encoding E box (5'-CACGTG-3')-binding protein from a rat granulosa cell cDNA library using a yeast one-hybrid system. When multiple E box sequences were used as target, we obtained a positive clone that encodes the rat homologue of upstream stimulatory factor 2 (USF2). An analysis of the nucleotide sequence and its deduced amino acid sequence reveals that rat USF2 protein consists of 346 amino acid residues and belongs to the basic helix-loop-helix/leucine zipper protein family. Northern blot analysis shows that rat USF2 mRNA exists as multiple forms between 1.6 and 2.2 kilobases. The size of the cloned insert was identical to that of the transcript of maximal length. Electrophoretic mobility shift assays showed that in vitro-translated rat USF2 specifically binds to the E box. In addition, cotransfection experiments with luciferase-reporter constructs in HepG2 cells reveal that the overexpression of rat USF2 leads to an increase of luciferase activity in the E box sequence-dependent manner. Thus, we report molecular cloning, expression, and functional characterization of full-length rat USF2 cDNA.

Acute effects of endothelin-1 and TAK-044 (ET(A) and ET(B) receptor antagonist) in rats with dilated cardiomyopathy

The hemodynamic effects of endothelin (ET)-1 and TAK-044 (ET(A) and ET(B) receptor antagonist) were studied in a rat model of dilated cardiomyopathy after autoimmune myocarditis. Six weeks after immunization, survived Lewis rats (30/43 = 70%) were randomly allocated into five groups to be given 0, 0.3, 3, 30 and 60 mg/kg/day (groups F0, F0.3, F3, F30 and F60; each group, n = 4) of TAK-044 using an osmotic pump subcutaneously. Age-matched normal Lewis rats (n = 26) were also randomly divided into four groups to be given 0, 0.3, 3 and 30 mg/kg/day (groups N0, N0.3, N3 and N30; each group, n = 4). ET-1 concentrations in plasma and myocardium were measured, and immunohistochemical detection of ET-1 in the left ventricle from the remaining rats (groups F and N) was performed. After administration of TAK-044 for 7 days, 2, 4, 11, 21 and 42 ng/min ET-1 every 20 min was infused using a pump, and the change in mean arterial pressure of each group during the infusion was examined. The plasma and myocardial ET-1 concentrations were significantly higher in group F than group N (12.3 +/- 1.5 vs. 5.4 +/- 0.2 pg/ml and 426 +/- 31 vs. 98 +/- 6 pg/g tissue; both p < 0.01). Strong positive signals for ET-1 were found to be widely distributed in the left ventricular myocardium of both groups of rats. Although the ET-1-induced increase in the mean arterial pressure was abolished in group N30, the maximal dose of ET-1 produced a 34% increase in the mean arterial pressure in group F30. Even in group F60, ET-1-induced hypertension was blocked incompletely. These results indicate that the heart may be a major ET-1-producing organ, and a higher dose of ET-1 antagonist is needed to block the effect of ET-1 in rats with dilated cardiomyopathy.

Novel G proteins, Rag C and Rag D, interact with GTP-binding proteins, Rag A and Rag B

Rag A/Gtr1p are G proteins and are known to be involved in the RCC1-Ran pathway. We employed the two-hybrid method using Rag A as the bait to identify proteins binding to Rag A, and we isolated two novel human G proteins, Rag C and Rag D. Rag C demonstrates homology with Rag D (81.1% identity) and with Gtr2p of Saccharomyces cerevisiae (46.1% identity), and it belongs to the Rag A subfamily of the Ras family. Rag C and Rag D contain conserved GTP-binding motifs (PM-1, -2, and -3) in their N-terminal regions. Recombinant glutathione S-transferase fusion protein of Rag C efficiently bound to both [(3)H]GTP and [(3)H]GDP. Rag A was associated with both Rag C and Rag D in their C-terminal regions where a potential leucine zipper motif and a coiled-coil structure were found. Rag C and D were associated with both the GDP and GTP forms of Rag A. Both Rag C and Rag D changed their subcellular localization, depending on the nucleotide-bound state of Rag A. In a similar way, the disruption of S. cerevisiae GTR1 resulted in a change in the localization of Gtr2p.

Verification of NEXAFS assignments by a comparison of fragmentation between gaseous and condensed methyl formate

According to the ion desorption from condensed methyl formate (DCOOCH3) by C 1s electron excitation, C+ yield was strongly enhanced at 289.1 eV, a higher energy side of C1s(DC) --> pi*(C=O) peak. This feature could not be clearly assigned. In this work, to clarify the feature, fragment-ion yield curves of gas-phase methyl formate were measured and compared with those of condensed one, since gas-phase and condensed systems are presumed to show more or less similar fragment-ion yield curves under similar excitations. The results demonstrate that fragment-ion yield curves are useful for the assignments of NEXAFS features in both gaseous and condensed polyatomic molecules.

A case of inability to belch

A 22-year-old man was unable to belch. He could sense intraesophageal gas, but had no chest pain. An upper gastrointestinal X-ray series and endoscopic examination showed no abnormalities. Esophageal manometry showed normal relaxation of both the upper and lower esophageal sphincters with primary peristalsis during deglutition. However, bolus injection of air into the middle esophagus failed to initiate the belch reflex.

Photon-stimulated ion desorption from molybdenum oxides following Mo 2p3/2 excitation

Photon-stimulated ion desorption from solid MoO3 following the Mo 2p3/2 resonant transition has been investigated. In the XANES spectrum, Mo 2p3/2 peak is split into two components corresponding to the excitations from Mo 2p3/2 into the t2g and e(g) orbitals. It was observed that the desorption yield of O+ ions at the Mo 2p3/2-->e(g) resonance is higher than that at the Mo 2p3/2-->t2g resonance. The Auger decay spectra reveal that there exist two kinds of spectator Auger decays. The high desorption yield at the 2p3/2-->e(g) resonance is interpreted by the fast breaking of the Mo-O bond due to the localization of the electrons in the highly antibonding e(g).