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The formation of giant planets requires the accumulation of ∼10 Earth masses in solids; but how do protoplanets acquire their mass? There are many, often competing, processes that regulate the accretion rate of protoplanets. To assess their effects we present a new, publicly available toy model. The rationale behind the toy model is that it encompasses as many physically relevant processes as possible, but at the same time does not compromise its simplicity, speed, and physical insight. The toy model follows a modular structure, where key features--e.g., planetesimal fragmentation, radial orbital decay, nebula turbulence--can be switched on or off. Our model assumes three discrete components (fragments, planetesimals, and embryos) and is zero dimensional in space.We have tested the outcomes of the toy model against literature results and generally find satisfactory agreement. We include, for the first time, model features that capture the three-way interactions among small particles, gas, and protoplanets. Collisions among planetesimals will result in fragmentation, transferring a substantial amount of the solid mass to small particles, which couple strongly to the gas. Our results indicate that the efficiency of the accretion process then becomes very sensitive to the gas properties--especially to the turbulent state and the magnitude of the disk headwind (the decrease of the orbital velocity of the gas with respect to Keplerian)--as well as to the characteristic fragment size. [ABSTRACT FROM AUTHOR]

In our solar system, Mars-sized protoplanets frequently collided with each other during the last stage of terrestrial planet formation, called the giant impact stage. Giant impacts eject a large amount of material from the colliding protoplanets into the terrestrial planet region, which may form debris disks with observable infrared excesses. Indeed, tens of warm debris disks around young solar-type stars have been observed. Here we quantitatively estimate the total mass of ejected materials during the giant impact stages. We found that ∼0.4 times the Earth’s mass is ejected in total throughout the giant impact stage. Ejected materials are ground down by collisional cascade until micron-sized grains are blown out by radiation pressure. The depletion timescale of these ejected materials is determined primarily by the mass of the largest body among them. We conducted high-resolution simulations of giant impacts to accurately obtain the mass of the largest ejected body. We then calculated the evolution of the debris disks produced by a series of giant impacts and depleted by collisional cascades to obtain the infrared excess evolution of the debris disks. We found that the infrared excess is almost always higher than the stellar infrared flux throughout the giant impact stage (∼100 Myr) and is sometimes ∼10 times higher immediately after a giant impact. Therefore, giant impact stages would explain the infrared excess from most observed warm debris disks. The observed fraction of stars with warm debris disks indicates that the formation probability of our solar-system-like terrestrial planets is approximately 10%. [ABSTRACT FROM AUTHOR]

Macrophages manifest distinct phenotype according to the organs in which they reside. In addition, they flexibly switch their character in adaptation to the changing environment. However, the molecular basis that explains the conversion of the macrophage phenotype has so far been unexplored. We find that CD169+ macrophages change their phenotype by regulating the level of a transcription factor Maf both in vitro and in vivo in C57BL/6J mice. When CD169+ macrophages were exposed to bacterial components, they expressed an array of acute inflammatory response genes in Maf-dependent manner and simultaneously start to downregulate Maf. This Maf suppression is dependent on accelerated degradation through proteasome pathway and microRNA-mediated silencing. The downregulation of Maf unlocks the NF-E2-related factor 2-dominant, cytoprotective/antioxidative program in the same macrophages. The present study provides new insights into the previously unanswered question of how macrophages initiate proinflammatory responses while retaining their capacity to repair injured tissues during inflammation. [ABSTRACT FROM AUTHOR]

The demand for precisely controlled etching is increasing as semiconductor device geometries continue to shrink. To fulfill this demand, cyclic atomic level/layer etching will become one of the key technologies in semiconductor device manufacturing at nanometer dimensions. This review describes recent trends in semiconductor devices and some of the latest results on cyclic atomic-level etching. In particular, it focuses on two types of cyclic etching that use different heating procedures: infrared irradiation for isotropic etching and Ar+ ion bombardment for anisotropic etching. It describes how an inductively-coupled-plasma down-flow etching apparatus with infrared lamps can be used for isotropic cyclic etching. The isotropic cyclic etching of SiN involves the formation and thermal desorption of ammonium hexafluorosilicate-based surface modified layers. This method features high selectivity with respect to SiO2, atomic-level control of the amount of SiN etching, and isotropic etched features. On the other hand, the anisotropic cyclic etching with Ar+ ion bombardment uses a microwave electron-cyclotron-resonance plasma etching apparatus. The anisotropic process for poly Si is composed of cyclic repetitions of chlorine adsorption and Ar+ ion bombardment. The anisotropic process for SiN is composed of cyclic repetitions involving an adsorption step using hydrofluorocarbon chemistry and a desorption step using Ar+ ion bombardment. Potential applications of these isotropic/anisotropic cyclic etching processes are described. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate viability of porcine embryos vitrified by the metal mesh vitrification (MMV) method after surgical or nonsurgical transfer. Prepubertal gilts were treated with eCG and hCG (= Day 0), and then inseminated artificially. Expanding blastocysts that were about 200 m in diameter were collected on Day 7. The embryos were equilibrated in 7.5% ethylene glycol (EG) + 7.5% DMSO + 20% fetal bovine serum (FBS) in PBS at 37C for 5 min, and then transferred into 15% EG + 15% DMSO + 0.6 M trehalose + 20% FBS in PBS for 1 min. Embryos in groups of 5 were transferred in a minimum volume of the vitrification solution (less than 1 L) onto stainless steel mesh (75 m screen size, 1.5 mm in width by 10 mm in length, with a 3-mm right-angle bend), and then plunged into liquid nitrogen. The mesh was stored in a 1.8-mL cryotube submerged in liquid nitrogen. Warming and dilution were performed by moving the mesh from liquid nitrogen into 0.5 M trehalose + 20% FBS in PBS at 37C for 5 min. Embryos were rinsed twice in NCSU37 + 10% FBS (mNCSU37) for 5 min. After being vitrified, embryos in groups of 20 per recipient were suspended in modified NCSU37 medium and then transferred into gilts either by surgical transfer (5 gilts) or by nonsurgical transfer (6 sows). For surgical transfer, embryos suspended in 0.1 mL of medium were transferred into the uterine horn at 15 cm above the uterine body, which was about 35 cm from the external uterine orifice. For nonsurgical transfer, an intrauterine catheter made from polyethylene tubing (1.2 m long, 3.0 mm outer diameter, 0.5 mm inner diameter) was used. A spiral guide inserted through the vagina into the cervix was used to guide the catheter into one uterine horn. The catheter was moved through the cervix and along the uterine horn. Then, embryos suspended in 1 mL of medium were transferred. Pregnancy was assessed by ultrasonography at 30 days post-estrus. With surgical transfer, 4 of 5 recipients became pregnant, and 3 gilts farrowed a total of 21 (10, 8, 3) live piglets; the fourth gilt aborted one fetus on Day 34. With nonsurgical transfer, 3 of 6 sows became pregnant. The present study demonstrates that vitrified porcine embryos can develop after both surgical and nonsurgical transfer to recipients. As a practical measure, nonsurgical transfer of vitrified porcine blastocysts may be used instead of surgical transfer. [ABSTRACT FROM AUTHOR]

Context. Proper motion observations of masers can provide information on dynamic motions on scales of a few milliarcseconds per year (mas yr-1) at radii of 100-1000 au scales from central young stellar objects (YSOs). Aims. The 6.7 GHz methanol masers are one of the best probes for investigations of the dynamics of high-mass YSOs, and in particular for tracing the rotating disk. We have measured the internal proper motions of the 6.7 GHz methanol masers associated with Cepheus A (Cep A) HW2 using Very Long Baseline Interferometery (VLBI) observations. Methods. We conducted three epochs of VLBI monitoring observations of the 6.7 GHz methanol masers in Cep A-HW2 with the Japanese VLBI Network (JVN) over the period 2006-2008. In 2006, we were able to use phase-referencing to measure the absolute coordinates of the maser emission with an accuracy of a few milliarcseconds. We compared the maser distribution with other molecular line observations that trace the rotating disk. Results. We measured the internal proper motions for 29 methanol maser spots, of which 19 were identified at all three epochs and the remaining ten at only two epochs. The magnitude of proper motions ranged from 0.2 to 7.4 km s-1, with an average of 3.1 km s-1. Although there are large uncertainties in the observed internal proper motions of the methanol maser spots in Cep A, they are well fitted by a disk that includes both rotation and infall velocity components. The derived rotation and infall velocities at the disk radius of 680 au are 0.5 ± 0.7 and 1.8 ± 0.7 km s-1, respectively. Conclusions. Assuming that the modeled disk motion accurately represents the accretion disk around the Cep A-HW2 high-mass YSO, we estimated the mass infall rate to be 3×10-4 n8 M☉ yr-1 (n8 is the gas volume density in units of 108 cm-3). The combination of the estimated mass infall rate and the magnitude of the fitted infall velocity suggests that Cep A-HW2 is at an evolutionary phase of active gas accretion from the disk onto the central high-mass YSO. The infall momentum rate is estimated to be 5 × 10-4 n8 M☉ yr-1 km s-1, which is larger than the estimated stellar radiation pressure of the HW2 object, supporting the hypothesis that this object is in an active gas accretion phase. [ABSTRACT FROM AUTHOR]

Abstract  Transgenic plants of Tricyrtis hirta carrying the intron-containing β-glucuronidase (GUS) gene under the control of the CaMV35S promoter have been cultivated for two years. Four independent transgenic plants produced flowers 1–2 years after acclimatization, and all of them contained one copy of the transgene as indicated by inverse polymerase chain reaction (PCR) analysis. All the four transgenic plants showed stable expression of the gus gene in leaves, stems, roots, tepals, stamens and pistils as indicated by histochemical and fluorometric GUS assays, although differences in the GUS activity were observed among different organs of each transgenic plant. No apparent gus gene silencing was observed in transgenic T. hirta plants even after two years of cultivation. [ABSTRACT FROM AUTHOR]

The antioxidant activity of catechin was amplified by conjugation with amine-terminated polyhedral oligomeric silsesquioxane (POSS) using horseradish peroxidase as catalyst. Compared to intact catechin, the scavenging activity of the POSS-catechin conjugate against superoxide anion was greatly improved. In addition, the conjugate strongly inhibited xanthine oxidase activity. [ABSTRACT FROM AUTHOR]

SHPS-1 is a transmembrane protein whose extracellular region interacts with CD47 and whose cytoplasmic region undergoes tyrosine phosphorylation and there by binds the protein tyrosine phosphatase SHP-2. Formation of this complex is implicated in regulation of cell migration by an unknown mechanism. A CD47-Fc fusion protein or antibodies to SHPS-1 inhibited migration of human melanoma cells or of CHO cells overexpressing SHPS-1. Overexpression of wild-type SHPS-1 promoted CHO cell migration, whereas expression of the SHPS-1-4F mutant, which lacks the phosphorylation sites required for SHP-2 binding, had no effect. Antibodies to SHPS-1 failed to inhibit migration of CHO cells expressing SHPS-1-4F. SHPS-1 ligands induced the dephosphorylation of SHPS-1 and dissociation of SHP-2. Antibodies to SHPS-1 also enhanced Rho activity and induced both formation of stress fibers and adoption of a less polarized morphology in melanoma cells. Our results suggest that engagement of SHPS-1 by CD47 prevents the positive regulation of cell migration by this protein. The CD47- SHPS-1 system and SHP-2 might thus contribute to the inhibition of cell migration by cell-cell contact. [ABSTRACT FROM AUTHOR]