Examining the process by which marital adjustment affects maternal warmth: The role of coparenting support as a mediator.

This study assessed the longitudinal process by which marital adjustment affects change in maternal warmth over time. Change in coparenting support was examined as the potential mechanism by which the marriage affects parenting. Self-report data were gathered from 148 married mothers of first-born 4th graders at 3 time points, over the transition to early adolescence. Path analyses supported the proposed hypothesis, indicating that marital adjustment leads to increased coparenting support, which then leads to increased maternal warmth. Two alternative models of the time-ordered direction of effects among the study variables were ruled out. This study has important implications for the development of parenting interventions targeting the promotion of maternal warmth. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Specialist's Role in Computer Training Programs

Without realizing it, many organizations offer their employees the same old computer training programs that no longer provide the knowledge today's computer users need to make the most efficient use of their systems. This column suggests one simple change to current training programs—namely sending the teachers (specialists) out of the computer classroom and to the students (users)—which can increase the users' confidence in the system and make them more productive.     

Local Structure and Properties of Oxide Surfaces: Scanning Probe Analyses of Ceramics

Scanning probe microscopies, especially scanning tunneling microscopy, were first directed to metal and semiconductor surfaces. Early challenges associated with the low conductivity and ionicity of oxides slowed application to even semiconducting ceramics. Recently, some of these obstacles have been overcome, and probe microscopies have been used to determine the atomic structures, as well as local properties, of many oxide surfaces and interfaces. Approaches to quantifying both tunneling spectroscopy and tunneling images of oxides are presented. Oxide surfaces accommodate nonstoichiometry via reconstruction or surface stabilization of substoichiometric phases. Effects of self-segregation and of impurity segregation on local properties of surfaces are observed directly. Three examples of local properties at interfaces are presented: contact potential at nanoscale metal cluster-oxide interfaces, local electrostatic fields at grain boundaries, and current flow in complex superconducting microstructures.     

Segregation in Yttrium Aluminum Garnet: I, Experimental Determination

Single crystals of yttrium aluminum garnet (YAG) that were doped with various cations were annealed in air at different temperatures for varying amounts of time. Dopants were chosen to probe the effect of size, charge, and site occupancy on surface segregation. Of the dopants that were chosen for the study (calcium, silicon, neodymium, chromium, and strontium), calcium was the only one that consistently segregated upon annealing in air. Calcium enrichment to the (111) surface was measured using Auger electron spectroscopy, and the segregation enthalpy was determined to be δ H _seg≈−32 ± 10 kJ/mol. Enrichment occurred according to variations in valence, as opposed to variations in size; therefore, it is suggested that surface segregation is electrostatically driven. The results indicate that aliovalent substituents could be used for interface property tailoring, whereas isovalent dopants would not be useful.     

The impact of identifier style on effort and comprehension

A family of studies investigating the impact of program identifier style on human comprehension is presented. Two popular identifier styles are examined, namely camel case and underscore. The underlying hypothesis is that identifier style affects the speed and accuracy of comprehending source code. To investigate this hypothesis, five studies were designed and conducted. The first study, which investigates how well humans read identifiers in the two different styles, focuses on low-level readability issues. The remaining four studies build on the first to focus on the semantic implications of identifier style. The studies involve 150 participants with varied demographics from two different universities. A range of experimental methods is used in the studies including timed testing, read aloud, and eye tracking. These methods produce a broad set of measurements and appropriate statistical methods, such as regression models and Generalized Linear Mixed Models (GLMMs), are applied to analyze the results. While unexpected, the results demonstrate that the tasks of reading and comprehending source code is fundamentally different from those of reading and comprehending natural language. Furthermore, as the task becomes similar to reading prose, the results become similar to work on reading natural language text. For more “source focused” tasks, experienced software developers appear to be less affected by identifier style; however, beginners benefit from the use of camel casing with respect to accuracy and effort.     

Clean electromigrated nanogaps imaged by transmission electron microscopy

Electromigrated nanogaps have shown great promise for use in molecular scale electronics. We have fabricated nanogaps on free-standing transparent SiN(x) membranes which permit the use of transmission electron microscopy (TEM) to image the gaps. The electrodes are formed by extending a recently developed controlled electromigration procedure and yield a nanogap with approximately 5 nm separation clear of any apparent debris. The gaps are stable, on the order of hours as measured by TEM, but over time (months) relax to about 20 nm separation determined by the surface energy of the Au electrodes. A major benefit of electromigrated nanogaps on SiN(x) membranes is that the junction pinches in away from residual metal left from the Au deposition which could act as a parasitic conductance path. This work has implications to the design of clean metallic electrodes for use in nanoscale devices where the precise geometry of the electrode is important.     

TLC and <Superscript>31</Superscript>P-NMR Analysis of Low Polarity Phospholipids

High-performance TLC and ³¹P-NMR were assessed as methods of observing the presence of numerous low polarity phospholipids: bis-phosphatidic acid (BPA), semi-lyso bis-phosphatidic acid (SLBPA), N-acyl phosphatidylethanolamine (NAPE), N-(1,1-dimethyl-3-oxo-butyl)-phosphatidylethanolamine (diacetone adduct of PE, DOBPE), N-acetyl PE, phosphatidylmethanol (PM), phosphatidylethanol (PEt), phosphatidyl-n-propanol (PP), phosphatidyl-n-butanol (PB). Both techniques are non-discriminative and do not require the prior isolation of individual lipids. It appears that 2D TLC is superior to ³¹P NMR in the analysis of low polarity phospholipids. All phosphatidylalcohols were well separated by 2D TLC. However, some compounds which can present difficulty in separation by 2D-TLC (e.g., SLBPA and NAPE; or DOBPE and N-acetyl PE) were easily distinguished using ³¹P NMR so the methods are complimentary. A disadvantage of 2D TLC is that Rf values can vary with different brands and batches of TLC plates. The chemical shifts of ³¹P NMR were less variable, and so a library of standards may not be necessary for peak identification. Another advantage of ³¹P NMR is the ease of quantification of phospholipids. The applicability of the methods was tested on natural extracts of fish brain and cabbage stem.     

Simulated behavior of multi-story X-braced frames

Steel braced frames are a commonly used seismic resisting system and thus, multi-story X-braced frames are frequently used. However, research into the behavior of these systems with midspan gusset plates, as used in practice, is limited. As a result, their seismic performance and the influence of connection design on this performance are not well understood. A comprehensive series of inelastic analyses were undertaken to better understand the nonlinear, cyclic behavior of multi-story X-braced frames and their gusset plate connections. Finite element (FE) analyses were conducted and the FE model was developed and verified by comparing the simulated results with cyclic tests and nonlinear analyses of single story systems, conducted at the University of Washington. The verified analytical model and associated failure estimation procedures were used to predict all yield mechanisms and failure modes, frame deformation capacity, and initial cracking and fracture of critical elements within the frame. A parametric study was performed to examine the influence of the gusset plate, framing members and other structural elements on the seismic performance of multi-story X-braced frames. The results show that the design and detailing of the gusset plate has a significant impact on the seismic performance of the frame. Connections designed with proposed end-rotational clearance models, and with strength and stiffness values balanced to the buckling and tensile yield capacities of the brace provided the best ductility and deformation capacity. In addition, the results suggest that floor slabs, gusset plate stiffeners and framing member sizes affect the frame performance and must be considered in the analysis and design of the system.     

The New Mechanical Engineering Curriculum at the University of Michigan

This paper describes the new undergraduate program in the Department of Mechanical Engineering and Applied Mechanics at the University of Michigan, Ann Arbor. The restructuring of the program was initiated by a comprehensive review in 1992 that included surveys of alumni, students, and industrial representatives, as well as faculty assessment of current trends and future needs. The program is intended to address the changing backgrounds of incoming students, to prepare the students for new and diverse challenges in the workplace, and to provide a structure for the curriculum to evolve with changing technology. The new curriculum consists of three integrated courses in Design and Manufacturing, two Laboratory courses, and several redesigned courses in the Engineering Sciences. The redesigned program provides students with extensive hands‐on experience, a comprehensive experience in teamwork and technical communication, and the opportunity to exercise and develop their creativity.