Formation of hybrid spin crossover polymer microspheres

We report the formation of hybrid metallopolymer microspheres, deposited from an acetonitrile solution containing a known iron(3+) spin crossover complex bearing a thienyl substituent. We characterize the metallopolymer using SEM, FT-IR, elemental analysis (including C, H, N, S, Fe analyses), small-angle X-ray scattering (SAXS) techniques, and PXRD. Of greatest significance, the polymeric microspheres also exhibit spin crossover, conferring on metallopolymer 2 the first spin crossover nanoscale material of its kind.     

Nanoscale precipitation and mechanical properties of Al-0.06 at.% Sc alloys microalloyed with Yb or Gd

Dilute Al-0.06 at.% Sc alloys with microalloying additions of 50 at. ppm of ytterbium (Yb) or gadolinium (Gd) are studied with 3D local-electrode atom-probe (LEAP) tomography for different aging times at 300 °C. Peak-aged alloys exhibit Al₃(Sc_1−x Yb _x ) or Al₃(Sc_1−x Gd _x ) precipitates (L1₂ structure) with a higher number density (and therefore higher peak hardness) than a binary Al-0.06 at.% Sc alloy. The Al–Sc–Gd alloy exhibits a higher number density of precipitates with a smaller average radius than the Al–Sc–Yb alloy, leading to a higher hardness. In the Al–Sc–Gd alloy, only a small amount of the Sc is replaced by Gd in the Al₃(Sc_1−x Gd _x ) precipitates, where x = 0.08. By contrast, the hardness incubation time is significantly shorter in the Al–Sc–Yb alloy, due to the formation of Yb-rich Al₃(Yb_1−x Sc _x ) precipitates to which Sc subsequently diffuses, eventually forming Sc-rich Al₃(Sc_1−x Yb _x ) precipitates. For both alloys, the precipitate radii are found to be almost constant to an aging time of 24 h, although the concentration and distribution of the RE elements in the precipitates continues to evolve temporally. Similar to microhardness at ambient temperature, the creep resistance at 300 °C is significantly improved by RE microalloying of the binary Al-0.06 at.% Sc alloy.     

A Study of the Social Security Work Incentives and Their Relation to Perceived Barriers to Work Among Persons With Psychiatric Disability.

Objective: To study use and awareness of the Social Security Work Incentives (SSWIs) and to obtain empirical data on barriers to returning to work. Study Design: Using parallel surveys and multiple sampling and recruitment strategies, the authors administered a brief survey about the SSWIs. Participants: Persons with a psychiatric disability (n=539), service providers (n=120), and family members (n=174). Results: All groups registered the greatest concern about the loss of health insurance; this and other concerns were perceived as serious barriers to returning to work. There were differences in the perceptions of the 3 groups about the importance of disincentives to work and differences among consumers by demographic characteristics. Conclusions: Consumers, family members, and providers of services need more information about the work incentives, particularly if the goals of the new Ticket to Work legislation are to be realized. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of GAC pre-treatment and disinfectant on microbial community structure and opportunistic pathogen occurrence

Opportunistic pathogens in potable water systems are an emerging health concern; however, the factors influencing their proliferation are poorly understood. Here we investigated the effects of prior granular activated carbon (GAC) biofiltration [GAC-filtered water, unfiltered water, and a blend (30% GAC filtered and 70% unfiltered water)] and disinfectant type (chlorine, chloramine) on opportunistic pathogen occurrence using five annular reactors (ARs) to simulate water distribution systems, particularly premise plumbing. GAC pre-treatment effectively reduced total organic carbon (TOC), resulting in three levels of influent TOC investigated. Quantitative polymerase chain reaction (q-PCR) provided molecular evidence of natural colonization of Legionella spp., Mycobacterium spp., Acanthamoeba spp., Hartmannella vermiformis and Mycobacterium avium on AR coupons. Cultivable mycobacteria and amoeba, including pathogenic species, were also found in bulk water and biofilm samples. While q-PCR tends to overestimate live cells, it provided a quantitative comparison of target organisms colonizing the AR biofilms in terms of gene copy numbers. In most cases, total bacteria and opportunistic pathogens were higher in the three undisinfected ARs, but the levels were not proportional to the level of GAC pre-treatment/TOC. Chlorine was more effective for controlling mycobacteria and Acanthamoeba, whereas chloramine was more effective for controlling Legionella. Both chlorine and chloramine effectively inhibited M. avium and H. vermiformis colonization. Pyrosequencing of 16S rRNA genes in coupon biofilms revealed a significant effect of GAC pre-treatment and disinfectant type on the microbial community structure. Overall, this study provides insights into the potential of different disinfectants and GAC biofilters at the treatment plant and in buildings to control downstream opportunistic pathogens and broader drinking water microbial communities.     

Exploiting resolution proofs to speed up LTL vacuity detection for BMC

When model-checking reports that a property holds on a model, vacuity detection increases user confidence in this result by checking that the property is satisfied in the intended way. While vacuity detection is effective, it is a relatively expensive technique requiring many additional model-checking runs. We address the problem of efficient vacuity detection for Bounded Model Checking (BMC) of linear temporal logic properties, presenting three partial vacuity detection methods based on the efficient analysis of the resolution proof produced by a successful BMC run. In particular, we define a characteristic of resolution proofs— peripherality—and prove that if a variable is a source of vacuity, then there exists a resolution proof in which this variable is peripheral. Our vacuity detection tool, VaqTree, uses these methods to detect vacuous variables, decreasing the total number of model-checking runs required to detect all sources of vacuity.     

Powder XRD, SEM, and Multinuclear MAS-NMR Investigations of the Interactions Between Glass and Crystalline Phases of Li, Na, or K Ceramic Waste Forms

Interactions between the glass and crystalline phases of ceramic waste forms were investigated via powder X-ray diffraction, scanning electron microscopy, and ²⁹Si, ²⁷Al, ²³Na, ⁷Li, and ³⁵Cl magic angle spinning nuclear magnetic resonance spectroscopy. LiCl, NaCl, or KCl waste form samples were made with or without glass. The waste forms containing glass consist of sodalite and glass phases with minor amounts of nepheline. Samples without glass form varying amounts of sodalite and nepheline. The glass frit, intended to bind the zeolite particles together, changes in composition, showing marked increases in aluminum and alkali content.     

Cognitive impairment influences drinking outcome by altering therapeutic mechanisms of change.

Serious neuropsychological impairments are seen in a minority of addiction treatment clients, and, theoretically, these impairments should undermine behavioral changes targeted by treatment; however, little evidence supports a direct influence of impairment on treatment response. To address this paradox, the authors used structural equation modeling and Project MATCH data (N=1,726) to examine direct, mediated, and moderated paths between cognitive impairment, therapeutic processes, and treatment outcome. Mediated relations were found, wherein impairment led to less treatment compliance, lower self-efficacy, and greater Alcoholics Anonymous Involvement, which, in turn, more proximally predicted drinking. Impairment further moderated the effect of self-efficacy, making it a poor predictor of drinking outcomes in impaired clients, thereby suggesting that impaired and unimpaired clients traverse different pathways to addiction recovery. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

PLANNING AND THE INTERGENERATIONAL COMMUNITY: Balancing the Needs of the Young and the Old in American Communities

ABSTRACT: Current federal policies have favored the resource needs of the elderly over the needs of child rearing families and children. Yet, federal policies are only part of the story. Can healthy intergenerational communities become a reality ? Is it possible for municipalities to help restore some balance in meeting the resource needs of the young and the old? The purpose of this article is to evaluate municipal land use, planning and zoning policies and the roles they play in meeting the needs of children and the elderly in contemporary American communities. Data collected in a nationwide zoning survey will be used to support the argument that communities are doing little to respond to the changing needs of child rearing and elderly families. The article concludes with a discussion of change strategies that could help make healthy intergenerational communities a reality.     

Change in maternal criticism and behavior problems in adolescents and adults with autism across a 7-year period.

In a previous study, high levels of maternal criticism predicted increased behavior problems in adolescents and adults with autism spectrum disorders (ASD) over an 18-month period (Greenberg, Seltzer, Hong, & Orsmond, 2006). The current investigation followed these families over a period of 7 years to examine the longitudinal course of criticism and behavior problems, to assess the association between their trajectories, and to determine the degree to which change in each of these factors predicted levels of criticism and behavior problems at the end of the study period. A sample of 118 mothers coresiding with their adolescent and adult children with ASD provided open-ended narratives about their children and reported on the children's behavior problems at 4 waves. Maternal criticism was derived from expressed emotion ratings of the narratives. Criticism exhibited low but significant stability over the 7-year period, and behavior problems exhibited high stability. Through latent growth curve modeling, (a) criticism was found to have increased over time, but only for the group of families in which the sons or daughters transitioned from high school services during the study period; (b) individual changes in criticism and behavior problems were positively correlated over the 7-year period; and (c) changes in criticism predicted levels of behavior problems at the conclusion of the study. Changes in behavior problems were not predictive of end levels of criticism. Implications for intervention and prevention efforts are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)