Effects of Hypergravity on Statocyst Development in Embryonic Aplysia californica

Aplysia californica is a marine gastropod mollusc with bilaterally paired statocysts as gravity-reccptor organs. Data from three experiments in which embryonic Aplysia californica were exposed to 2 x g arc discussed. The experimental groups were exposed to excess gravity until hatching (9-12 day), whereas control groups were maintained at normal gravity. Body diameter was measured before exposure to 2 x g. Statocyst, statolith and body diameter were each determined for samples of 20 embryos from each group on successive days. Exposure to excess gravity led to an increase in body size. Statocyst size was not affected by exposure to 2 x g. Statolith size decreased with treatment as indicated by smaller statolith-to-body ratios observed in the 2 x g group in all three experiments. Mean statolith diameter was significantly smaller for the 2 x g group in Experiment 1 but not in Experiments 2 and 3. Defective statocysts, characterized by very small or no statoliths, were found in the 2 x g group in Experiments 1 and 2

The Value of Smarter Teachers: International Evidence on Teacher Cognitive Skills and Student Performance

Differences in teacher quality are commonly cited as a key determinant of the huge international student performance gaps. However, convincing evidence on this relationship is still lacking, in part because it is unclear how to measure teacher quality consistently across countries. We use unique international assessment data to investigate the role of teacher cognitive skills as one main dimension of teacher quality in explaining student outcomes. Our main identification strategy exploits exogenous variation in teacher cognitive skills attributable to international differences in relative wages of nonteacher public sector employees. Using student-level test score data, we find that teacher cognitive skills are an important determinant of international differences in student performance. Results are supported by fixed-effects estimation that uses within-country between-subject variation in teacher skills

Pinning Force Scaling Analysis of Polycrystalline MgB2

Flux pinning force scaling f=Fp/Fp,max vs. h = Ha/Hirr was performed on a variety of pure MgB2 samples, including a spark plasma sintered (SPS) one and a series of samples sintered at various reaction temperatures ranging between 775 and 950 ∘C. The SPS sample exhibits a well-developed scaling at all temperatures, and also the sintered samples prepared at 950 ∘C; however, the obtained peak positions of the pinning force scalings are distinctly different: The SPS sample reveals dominating pinning at grain boundaries, whereas the dominating pinning for the other one is point-pinning. All other samples studied reveal an apparent non-scaling of the pinning forces. The obtained pinning parameters are discussed in the framework of the Dew–Hughes’ pinning force scaling approach

Beyond Books 2: Cataloging Archival Materials

Academic libraries aren’t the only institutions that care for archival materials. These unique items can often be found in public libraries, historical societies, and other cultural heritage organizations, many of which may not have trained special collections catalogers on staff. In this workshop, participants will learn how to catalog archival materials, including manuscripts, photographs, and audiovisual materials, so they can be discovered in online catalogs and databases. Both item and collection-level cataloging will be discussed, and participants will learn when and how to apply relevant metadata standards like RDA and DACS. They will then practice cataloging with examples provided by the instructors

A preliminary design study of a microparticle accelerator final report, 30 jan. - 13 apr. 1964

Design study for 2MV microparticle accelerato

The Revised DACS Principles in Action: Applying Modern Practice to Legacy Description

Since SAA revised DACS\u27s archival description principles from 8 concepts into 11 reworked value statements in 2019, archivists have wondered how to incorporate the revised principles into existing description practices. Archivists from BYU and USU libraries have undertaken large projects on legacy collections informed by these principles. We invite attendees to learn from our experiences in implementing current DACS principles while grappling with less-than-ideal records. BYU will describe a project to revise the description of a significant collection of Mesoamerican materials after discovering the finding aid had serious problems introduced by previous revisions by archivists. USU will describe an undertaking to create over 2,500 University Archives collection descriptions from a shelf list and revising based on the new DACS principles. This joint session will demonstrate straightforward ways that two academic libraries have incorporated the DACS principles into archivists\u27 day-to-day work

Communications Biophysics

Contains reports on four research projects.National Institutes of Health (Grant 1 P01 GM-14940-02)Joint Services Electronics Programs (U. S. Army, U. S. Navy, and U. S. Air Force) under Contract DA 28-043-AMC-02536(E)National Institutes of Health (Grant 5 TO1 GM-01555-02

The intergenerational transmission of cognitive skills: an investigation of the causal impact of families on student outcomes

The extensive literature on intergenerational mobility highlights the importance of family linkages but fails to provide credible evidence about the underlying family factors that drive the pervasive correlations. We employ a unique combination of Dutch survey and registry data that links math and language skills across generations. We identify a causal connection between cognitive skills of parents and their children by exploiting within-family between-subject variation in these skills. The data also permit novel IV estimation that isolates variation in parental cognitive skills due to school and peer quality. The between-subject and IV estimates of the key intergenerational persistence parameter are strikingly similar and close at about 0.1. Finally, we show the strong influence of family skill transmission on children’s choices of STEM fields