Strong genetic influences on the stability of autistic traits in childhood

Objective: Disorders on the autism spectrum, as well as autistic traits in the general population, have been found to be both highly stable across age and highly heritable at individual ages. However, little is known about the overlap in genetic and environmental influences on autistic traits across age and the contribution of such influences to trait stability itself. The present study investigated these questions in a general population sample of twins. Method: More than 6,000 twin pairs were rated on an established scale of autistic traits by their parents at 8, 9, and 12 years of age and by their teachers at 9 and 12 years of age. Data were analyzed using structural equation modeling. Results: The results indicated that, consistently across raters, not only were autistic traits stable, and moderately to highly heritable at individual ages, there was also a high degree of overlap in genetic influences across age. Furthermore, autistic trait stability could largely be accounted for by genetic factors, with the environment unique to each twin playing a minor role. The environment shared by twins had virtually no effect on the longitudinal stability in autistic traits. Conclusions: Autistic traits are highly stable across middle childhood and this stability is caused primarily by genetic factors

Social Status, Stature, and Pathology at Chucalissa (40SY1), Shelby County, Tennessee

Ethnohistoric and archaeological models have been used in making inferences about social interaction and relationships in Mississippian societies. In spite of an increasing awareness of cultural and biological interrelationships in approaching prehistoric societies, there remains a general lack of skeletal studies which have contributed to or supported these inferences. The purpose of this investigation was to test the hypothesis that socially regulated or defined differences between groups of individuals existed at Chucalissa (40SY1), incorporating both archaeological and skeletal data. The ethnohistoric model of the Natchez social system and Ford\u27s (1974:406) generalization that Mississippian societies were highly stratified due to a redistributional economy were evaluated for their applicability to Chucalissa. The sample consisted of 162 individuals, for which there were skeletal remains or recorded burial information. Most burials were thought to be Late Mississippian. Working from the assumption that differential burial treatment relays social meaning, burial data were examined for clues to social interaction and status. Stature and general pathological conditions were considered as their distributions have been attributed to the effects of social interaction or status. No apparent differences were found between residential units to suggest that they may have represented distinct social units. However, high status was inferred for the individuals of the burial mound because of their unique grave associations and the variability encountered among burial attributes. The high percentages of nonspecific inflammation of the appendicular skeleton, degenerative joint disease, and healed fractures found among these individuals may have been related to activities of acquiring or maintaining this high status. The tallest males and females were found in this burial mound. The distribution of pottery suggests that status may have been acquired at birth, but full social position was probably not realized until one reached adult status. The greater variability in burial attributes among subadults implies their tenuous social position. The high frequency of pottery among females and the high percentage of degenerative changes affecting synovial joints and healed fractures among males suggest that the major social distinction between males and females may have been a division of labor. From these results, it was concluded that neither the model of the Natchez social system nor Ford\u27s (1974:406) generalization that Mississippian societies were highly stratified due to a redistributional economy offered adequate interpretations of the data from Chucalissa

F-Element Binolate Complexes: Control of Secondary Structure for Applications in Redox Chemistry, Complex Design, and Asymmetric Catalysis

Rare earth elements (REs; Sc, Y, La - Lu) are critical components to many current applications and technologies making the synthesis of molecular compounds with specific and tunable properties highly desirable. However, control of the coordination environment of REs can be challenging, due to the ionic nature of the metal-ligand bonds. Our studies have focused on the introduction of non-covalent interactions in the secondary coordination sphere of f-element BINOLate complexes, which enabled controlled f-element coordination environments in heterobimetallic and hydrogen-bonded frameworks. Reactivity and properties were tunable by interactions in the secondary coordination sphere, and had immediate applications to redox chemistry, coordination chemistry and asymmetric catalysis. Detailed spectroscopic and mechanistic studies were undertaken to understand the role of these interactions, and provide guiding design principles for future systems and applications

Thermal coatings for titanium-aluminum alloys

Titanium aluminides and titanium alloys are candidate materials for use in hot structure and heat-shield components of hypersonic vehicles because of their good strength-to-weight characteristics at elevated temperature. However, in order to utilize their maximum temperature capability, they must be coated to resist oxidation and to have a high total remittance. Also, surface catalysis for recombination of dissociated species in the aerodynamic boundary layer must be minimized. Very thin chemical vapor deposition (CVD) coatings are attractive candidates for this application because of durability and very light weight. To demonstrate this concept, coatings of boron-silicon and aluminum-boron-silicon compositions were applied to the titanium-aluminides alpha2 (Ti-14Al-21Nb), super-alpha2 (Ti-14Al-23-Nb-2V), and gamma (Ti-33Al-6Nb-1Ta) and to the titanium alloy beta-21S (Ti-15Mo-3Al-3Nb-0.2Si). Coated specimens of each alloy were subjected to a set of simulated hypersonic vehicle environmental tests to determine their properties of oxidation resistance, surface catalysis, radiative emittance, and thermal shock resistance. Surface catalysis results should be viewed as relative performance only of the several coating-alloy combinations tested under the specific environmental conditions of the LaRC Hypersonic Materials Environmental Test System (HYMETS) arc-plasma-heated hypersonic wind tunnel. Tests were also conducted to evaluate the hydrogen transport properties of the coatings and any effects of the coating processing itself on fatigue life of the base alloys. Results are presented for three types of coatings, which are as follows: (1) a single layer boron silicon coating, (2) a single layer aluminum-boron-silicon coating, and (3) a multilayer coating consisting of an aluminum-boron-silicon sublayer with a boron-silicon outer layer

Public Perceptions of the Midwest’s Pavements: Policies and Thresholds

A 5-year, pooled fund study with the Iowa, Minnesota, and Wisconsin departments of transportation assessed the public\u27s perceptions of pavement improvement strategies and developed thresholds of satisfaction using the departments\u27 physical indices, such as pavement ride and condition on rural, two-lane highways in the states. Approximately 3,600 drivers in the three states were involved in the three phases of the project, which included 18 focus groups, 400 statewide surveys in each state, and 2,300 targeted surveys across the three states. A multidisciplinary team from Marquette University and a mass media survey lab conducted the studies. A summary of focus group methods and purposes and a three-state summary of policy and improvement issues are provided. More than 450 highway segments were surveyed in Phase III, with input from 2,300 drivers through a two-step recruitment and postdrive interview. Thresholds of International Roughness Index and condition indices are summarized for the three states. The study found a high degree of trust in the three departments of transportation and public support for building longer-lasting pavements and minimizing delay. A three-step methodology is recommended for other state studies. Physical data thresholds using both public satisfaction and the agreement to improve are presented for each state\u27s physical pavement indices (ride and condition)

Public Perceptions of Wisconsin’s Pavements and Tradeoffs in Pavement Improvement

Findings are reported from Phase II of a three-phase pooled-fund project in Wisconsin, Iowa, and Minnesota to determine perceptions of drivers regarding pavement of rural two-lane highways. Among the survey topics were drivers\u27 trust in the state department of transportation (DOT), pavement improvement trade-offs, and pavement evaluation. Results of the Wisconsin portion of the survey data are the focus of this study. The survey questionnaire was based in part on Phase I focus groups conducted to gauge beliefs about pavements as well as the language describing ruts, tining, and other pavement characteristics. Phase II entailed a statewide telephone survey of at least 400 randomly selected drivers in each of the three states. Although the focus here is on Wisconsin results, survey responses across the three states were very consistent. Included in the findings discussed are perceptions of pavement and the state DOT and pavement improvement options relating to construction, travel time, and delays. Results disclose key public perceptions of priorities with regard to spending limited funds. Also discussed are statistically significant relationships providing additional insights into public perceptions and pavement improvement on rural two-lane highways

Public Perceptions of the Midwest’s Pavements - Minnesota - Executive Summary

This report summarizes Minnesota results of a five year, Pooled Fund study involving the Wisconsin, Iowa, and Minnesota DOTs designed to 1) assess the public\u27s perceptions of the departments’ pavement improvement strategies and 2) to develop customer-based thresholds of satisfaction with pavements on rural two lane highways in each state as related to the Departments’ physical indices, such as pavement ride and condition. The primary objective was to seek systematic customer input to improve the Departments’ pavement improvement policies by 1) determining how drivers perceive the departments’ pavements in terms of comfort and convenience but also in terms of other tradeoffs departments had not previously considered, 2) determining relationships between perceptions and measured pavement condition thresholds (including a general level of tolerance of winter ride conditions in two of the states), and 3) identifying important attributes and issues that may not have been considered in the past. Secondary objectives were 1) to provide a tool for systematic customer input in the future and 2) provide information which can help structure public information programs. A University of Wisconsin-Extension survey lab conducted the surveys under the direction of a multi-disciplinary team from Marquette University. Approximately 4500 drivers in the three states participated in the three phases of the project. Researchers conducted six focus groups in each state, approximately 400 statewide telephone interviews in each state and 700-800 targeted telephone interviews in each state. Approximately 400 winter ride interviews were conducted in Wisconsin and Minnesota. A summary of the method for each survey is included. In Phase I, focus groups were conducted with drivers to get an initial indication of what the driving public believes in regards to pavements and to frame issues for inclusion in the more representative state-wide surveys of drivers conducted in Phase II of the project. Phase II interviews gathered information about improvement policy trade-off issues and about preliminary thresholds of improvement in terms of physical pavement indices. In Phase III, a two-step recruitment and post-drive interview procedure yielded thresholds of ride and condition index summarized for each state. Results show that, in general, the driving public wants longer lasting pavements and are willing to pay for them. They want to minimize construction delay, improve entire sections of highway at one time but they dislike detours, and prefer construction under traffic even if it stretches out construction time. Satisfaction with pavements does not correlate directly to a high degree with physical pavement indices, but was found instead to be a complex, multi-faceted phenomenon. A psychological model (after Fishbein/Ajzen) was applied to explain satisfaction to a respectable degree (R2 of .67) for the social sciences. Results also indicate a high degree of trust in the three DOTs which is enhanced when the public is asked for input on specific highway segments. Conclusions and recommendations include a three-step methodology for other state studies. Physical data thresholds based on both public satisfaction and the agreement to improve are presented for each state\u27s physical pavement indices (ride and condition). Recommendations for changes to the quality ranges of the physical indices where appropriate are also made

Public Perceptions of the Midwest’s Pavements - Iowa - Phase III

There are several objectives to this report. The first objective is to describe the sample with regard to the physical pavement data and three measures of driver satisfaction. In this section, the proportion of respondents who are satisfied with pavements on two-lane, rural, state highways will be examined and the distribution of pavement condition and roughness indices will be presented. The second objective will be a short description of the highway segments and any differences in satisfaction found between regions and pavement types. This was done in Phase II in each state and a letter sent showing the results in all three states. That letter sets forth the revised work plan and budget for Phase III of the project. The third objective is to describe the relationship between physical pavement characteristics and driver satisfaction. This will include a description of both the magnitude of relationship as well as identifying critical International Road Index (IRI) and Pavement Condition Index (PCI) cutoffs where a majority of the sample were satisfied. This will be done for comparative purposes with the Phase II approach, using the total sample to compute cumulative percentages responding to each of the three series of satisfaction questions