The U.S. demographic transition

agriculture;manufacturing;technological change

Engines of liberation

women;technological change

How Useful are High-Precision Delta ?17O Data in Defining the Asteroidal Sources of Meteorites?: Evidence from Main-Group Pallasites, Primitive and Differentiated Achondrites

High-precision oxygen isotope analysis is capable of revealing important information about the relationship between different meteorite groups. New data confirm that the main-group pallasites are from a distinct source to either the HEDs or mesosiderites

Synthesis of aromatic secondary diamines

A series of N-methyl substituted aromatic polyamides derived from the secondary aromatic diamines, 4,4'-bis(methylamino)diphenylmethane, 3,3'-bis(methylamino) diphenylmethane, 4,4'-bis(methylamino)benzophenone or 3,3'-bis(methylamino)benzophenone and isophthaloyl dichloride, terphthaloyl dichloride or 3,3'diphenylmethane dicarboxylic acid dichloride was prepared by high temperature solution polymerization in s-tetrachloroethane. Compared to analogous unsubstituted and partially N-methylated aromatic polyamides, the full N-methylated polyamides exhibited significantly lower glass transition temperatures, reduced crystallinity, improved thermal stability and good solubility in chlorinated solvents

“We could end up in a lot of trouble” Teachers’ communications with young children about mental health

Purpose – Stigma towards people with mental health problems is a significant problem and appears trenchant despite recent anti-stigma campaigns. Attitudes develop in young children, and may be stronger and less malleable in adolescence. Early intervention may be important for mental health education and stigma prevention. Theory, evidence and practical considerations suggest that teachers’ involvement is key. By exploring communication about mental health between teachers and young children, it will be possible to elaborate how stigma develops and may be ameliorated. This study explored teachers’ accounts of this communication and the factors that influence it. Methodology – Semi-structured interviews with fifteen primary school teachers were transcribed and analysed using a grounded theory approach. Findings – Discussions about mental health were largely absent from the classroom, due to teachers’ anxiety. Teachers felt the need to protect children from exposure to people with mental health problems and even from information about the topic, believed they lacked the necessary expertise, worried that such discussions were outside their remit, and were anxious about parents’ reactions. Originality/Value – This was the first study to interview teachers on this topic and suggests that a significant opportunity to address stigma is being missed. Teachers’ silence may reinforce that mental health problems are taboo, and prevent children from developing knowledge and a language to talk about mental health. The inclusion of teachers in early mental health education is more sustainable and could promote more inclusive attitudes, especially if supported by educational policy and curriculum. Keywords - school, young children, teachers, mental health education, stigma prevention, policy, grounded theory Article Classification – Research Pape

The measurement of the winds near the ocean surface with a radiometer-scatterometer on Skylab

The author has identified the following significant results. There were a total of twenty-six passes in the ZLV mode that yielded useful data. Six were in the in-track noncontiguous mode; all others were in the cross-track noncontiguous mode. The wind speed and direction, as effectively determined in a neutral atmosphere at 19.5 m above the sea surface, were found for each cell scanned by S193. It is shown how the passive microwave measurements were used both to compute the attenuation of the radar beam and to determine those cells where the backscatter measurement was suspect. Given the direction of the wind from some independent source, with the typical accuracy of measurement by available meteorological methods, a backscatter measurement at a nadir angle of 50, 43, or 32 deg can be used to compute the speed of the wind averaged over the illuminated area

Dry Friction due to Adsorbed Molecules

Using an adiabatic approximation method, which searches for Tomlinson model-like instabilities for a simple but still realistic model for two crystalline surfaces in the extremely light contact limit, with mobile molecules present at the interface, sliding relative to each other, we are able to account for the virtually universal occurrence of "dry friction." The model makes important predictions for the dependence of friction on the strength of the interaction of each surface with the mobile molecules.Comment: four pages of latex, figure provide

Oxygen Isotopic Constraints on the Number and Origin of Basaltic Achondrite Parent Bodies

Our data show that HED meteorites have a homogeneous oxygen isotopic composition consistent with a magma ocean on Vesta. Ibitira, Asuka 881394, Pasamonte, and NWA 1240 probably come from separate parent asteroids