Circumplanetary disks around young giant planets: a comparison between core-accretion and disk instability

Circumplanetary disks can be found around forming giant planets, regardless of whether core accretion or gravitational instability built the planet. We carried out state-of-the-art hydrodynamical simulations of the circumplanetary disks for both formation scenarios, using as similar initial conditions as possible to unveil possible intrinsic differences in the circumplanetary disk mass and temperature between the two formation mechanisms. We found that the circumplanetary disks mass linearly scales with the circumstellar disk mass. Therefore, in an equally massive protoplanetary disk, the circumplanetary disks formed in the disk instability model can be only a factor of eight more massive than their core-accretion counterparts. On the other hand, the bulk circumplanetary disk temperature differs by more than an order of magnitude between the two cases. The subdisks around planets formed by gravitational instability have a characteristic temperature below 100 K, while the core accretion circumplanetary disks are hot, with temperatures even greater than 1000 K when embedded in massive, optically thick protoplanetary disks. We explain how this difference can be understood as the natural result of the different formation mechanisms. We argue that the different temperatures should persist up to the point when a full-fledged gas giant forms via disk instability, hence our result provides a convenient criteria for observations to distinguish between the two main formation scenarios by measuring the bulk temperature in the planet vicinity.Comment: 12 pages, 9 figures, 1 table, accepted for publication at MNRA

Total and partial cross sections of the 112^{112}Sn(α,γ\alpha,\gamma)116^{116}Te reaction measured via in-beam γ\gamma-ray spectroscopy

An extended database of experimental data is needed to address uncertainties of the nuclear-physics input parameters for Hauser-Feshbach calculations. Especially $\alpha$+nucleus optical model potentials at low energies are not well known. The in-beam technique with an array of high-purity germanium (HPGe) detectors was successfully applied to the measurement of absolute cross sections of an ($\alpha$,$\gamma$) reaction on a heavy nucleus at sub-Coulomb energies. The total and partial cross-section values were measured by means of in-beam $\gamma$-ray spectroscopy. Total and partial cross sections were measured at four different $\alpha$-particle energies from $E_\alpha = 10.5$ MeV to $E_\alpha = 12$ MeV. The measured total cross-section values are in excellent agreement with previous results obtained with the activation technique, which proves the validity of the applied method. The experimental data was compared to Hauser-Feshbach calculations using the nuclear reaction code TALYS. A modified version of the semi-microscopic $\alpha$+nucleus optical model potential OMP 3, as well as modified proton and $\gamma$ widths, are needed in order to obtain a good agreement between experimental data and theory. It is found, that a model using a local modification of the nuclear-physics input parameters simultaneously reproduces total cross sections of the $^{112}$Sn($\alpha$,$\gamma$) and $^{112}$Sn($\alpha$,p) reactions. The measurement of partial cross sections turns out to be very important in this case in order to apply the correct $\gamma$-ray strength function in the Hauser-Feshbach calculations. The model also reproduces cross-section values of $\alpha$-induced reactions on $^{106}$Cd, as well as of ($\alpha$,n) reactions on $^{115,116}$Sn, hinting at a more global character of the obtained nuclear-physics input.Comment: 8 pages, 9 figure

Why do households without children support local public schools? linking house price capitalization to school spending

While residents receive similar benefits from many local public expenditures, only about one-third of all households have children in the public schools. In this paper the authors argue that capitalization of school spending into house prices can encourage residents to support spending on schools, even if the residents themselves will never have children in the schools. To examine this hypothesis, the authors take advantage of differences across communities in the extent of house price capitalization based on the availability of land or population density. They show that fiscal variables and amenities are capitalized to a much greater extent in Massachusetts cities and towns with little available land and that these localities also spend more on schools. Next, the authors use data from school districts in 49 states to show that per pupil spending is positively related to population density, a proxy for the availability of land. Consistent with a model tying house price capitalization to school spending, the authors show that the positive correlation between density and spending persists only in locations with high homeownership rates. Communities with a higher percentage of residents above 65 years old have increased school expenditures only in places with high population densities, and this correlation grows for the percentage of elderly above 75 or 85 years old who have a shorter expected duration in their house. The positive relationship between percentage elderly and school spending is confined to central cities and suburbs of large metropolitan areas and does not exist in places where land for new construction may be easier to obtain. These results support models in which house price capitalization encourages more efficient provision of public services and provide an explanation for why some elderly residents might support local spending on schools.Education

Influence of atomic mixing and preferential sputtering on depth profiles and interfaces

Atomic mixing and preferential sputtering impose a depth resolution limit on the use of sputter sectioning to measure the composition of metal–semiconductor interfaces. Experimental evidence obtained with the Pt–Si system is used to demonstrate ion‐induced atomic mixing and then its effect on sputter etching and depth profiling. Starting with discrete layer structures, a relatively low ion dose (≳3×10^(15) cm^(−2)) first produced a mixed surface layer with thickness comparable to the ion range. Higher ion doses then result in successive sputter etching and continual atomic mixing over a constant surface layer thickness. A model is developed that is based on a sputter removal (including preferential sputtering) of atoms at the surface and a uniform mixing of atoms over a constant thickness. The model predicts the influences of atomic mixing and preferential sputtering on the depth profiling of thin‐film structures and interfaces

Why Do Households Without Children Support Local Public Schools?

While residents receive similar benefits from many local government programs, only about one-third of all households have children in public schools. We argue that capitalization of school spending into house prices can encourage residents to support spending on schools, even if the residents themselves will never have children in schools. We identify a proxy for the extent of capitalization—the supply of land available for new development—and show that in response to a plausibly exogenous spending shock in Massachusetts, towns with little undeveloped land have larger changes in house prices, but smaller changes in quantity (construction). Towns with little available land also spend more on schools. We extend these results using data from school districts in 46 states, showing that per pupil spending is positively related to the percentage of developed land. This positive correlation persists only in districts where the median resident is a homeowner and is stronger in districts with more elderly residents who do not use school services and have a shorter expected duration in their home. These findings support models in which house price capitalization encourages more efficient provision of public services and may explain why some elderly residents support school spending.

Detection of HIV-1 infection in dried blood spots from a 12-year-old ABO bedside test card

Background and Objectives: We tested dried blood from an ABO bedside test card which had been stored at room temperature for 12 years, to prove that a patient with HIV-1 infection had been infected by blood transfusion. Materials and Methods: Immunoblots for HIV-1 antibodies and threefold PCRs with half-nested primers for the HIV-1 integrase gene were done with eluates from the dried blood spots. Results: HIV-1 antibodies and HIV-1 DNA could be detected in the sample from one unit of blood, but not from the two other units or from the recipient before transfusion. Conclusion: Further studies should be done on the validity of stored dried blood as an alternative to the storage of frozen donor serum for several years for `look-back' studies

The Emotional Self-Efficacy Scale: Adaptation and Validation for Young Adolescents

Emotional self-efficacy (ESE) is an important aspect of emotional functioning, with current measures for children and adolescents focused on the measurement of self-beliefs in relation to the management of emotions. In the present study, we report the psychometric properties of the first adaptation of the Emotional Self-Efficacy Scale for youth (Youth-ESES) that measures additional aspects of ESE, such as perceiving and understanding emotions and helping others modulate their emotions. Participants were 192 young adolescents aged 11 to 13 years from a U.K. state school. They completed the Youth-ESES and measures of ability emotional intelligence (EI) and cognitive ability. Results support the same four-factor structure that has been previously documented using the adult version of the ESES, with the four subscales being largely independent from cognitive ability and only moderately related to ability EI. However, the four subscales were less differentiated in the present study compared with adult data previously published, suggesting that there is a strong general factor underlying young adolescents’ ESE scores. Overall, the results suggest that the adapted Youth-ESES can be reliably used with youth, and that confidence in how a young person feels about his or her emotional functioning remains distinct from emotional skill

Constraints on the Formation of the Planet Around HD188753A

The claimed discovery of a Jupiter-mass planet in the close triple star system HD 188753 poses a problem for planet formation theory. A circumstellar disk around the planet's parent star would be truncated close to the star, leaving little material available for planet formation. In this paper, we attempt to model a protoplanetary disk around HD 188753A using a fairly simple alpha-disk model, exploring a range of parameters constrained by observations of T Tauri-type stars. The disk is truncated to within 1.5 to 2.7 AU, depending on model parameters. We find that the in situ formation of the planet around HD 188753A is implausible.Comment: Accepted version, to appear in ApJ. 23 pages, 5 figures (3 in color