A preliminary investigation of the molten salt mediated synthesis of Gd2TiO5 ‘stuffed’ pyrochlore

Refractory ‘stuffed’ pyrochlores such as Gd2TiO5 are of interest for nuclear applications, including as matrices for actinide disposition and as neutron absorbers in control rods. Here, we report the results of a preliminary comparative investigation of the synthesis of Gd2TiO5 by molten salt and conventional solid-state synthesis. We show that synthesis of Gd2TiO5 proceeds from the pyrochlore phase Gd2Ti2O7 which is first formed as a kinetic product. Molten salt synthesis afforded single phase Gd2TiO5 at 1300 °C in 2 h, via a template growth mechanism, and is effective for the synthesis of these refractory materials. This work demonstrates molten salt mediated synthesis of ‘stuffed’ pyrochlore for the first time

Trajectories of child protective services contact among Alaska Native/American Indian and non-Native children

Background: Contact with child protective services (CPS) functions as an independent marker of child vulnerability. Alaska children are an important population for understanding patterns of CPS contact given high rates of contact overall and among specific demographic groups. Objective: We aimed to identify longitudinal trajectory classes of CPS contact among Alaska Native/American Indian (AN/AI) and non-Native children and examine preconception and prenatal risk factors associated with identified classes. Participants and setting: We used data from the Alaska Longitudinal Child Abuse and Neglect Linkage (ALCANLink) project, a linkage of 2009–2011 Alaska Pregnancy Risk Assessment Monitoring System (PRAMS) births with administrative data including CPS records. Methods: We conducted growth mixture modeling to identify trajectory classes of CPS contact from birth to age five years. We used Vermunt's three-step approach to examine associations with preconception and prenatal risk factors. Results: Among AN/AI children, we identified three classes: 1) no/low CPS contact (75.4%); 2) continuous CPS contact (19.6%), and 3) early, decreasing CPS contact (5.0%). Among non-Native children, we identified four classes: 1) no CPS contact (81.3%); 2) low, increasing CPS contact (9.5%); 3) early, rapid decline CPS contact (5.8%); and 4) high, decreasing CPS contact (3.3%). Maternal substance use had the largest impact on probabilities of class membership, increasing the probability of membership in classes characterized by CPS contact, among both AN/AI and non-Native children. Conclusions: Results reveal heterogeneity in longitudinal patterns CPS contact across early childhood among Alaska children and identify maternal substance use as an important target for primary prevention

Preconception and Prenatal Predictors of Early Experiences of Risk and Protection Among Alaska Children

Objectives: Our objective was to identify preconception and prenatal predictors of early experiences of co-occurring risk and protective factors to help target prevention efforts to the highest-need families prior to the birth of the child. Methods: Data were from the Alaska Longitudinal Child Abuse and Neglect Linkage project and the 2012–2014 Alaska Child Understanding Behaviors Survey. We used latent class analysis and Vermunt’s three-step approach to examine predictors of latent classes of risk and protective factors among Alaska children. Results: Among children of Alaska Native/American Indian mothers, financial (OR 2.02, 95% CI 1.04, 3.90) and partner stress (OR 2.06, 95% CI 1.02, 4.10) prior to childbirth, maternal education < 12 years (OR 2.29, 95% CI 1.05, 4.96), and maternal substance use (OR 2.52, 95% CI 1.30, 4.89) were associated with a higher likelihood of membership in a high risk/moderate protection class as compared to a low socioeconomic status/high protection class. Among children of non-Native mothers, partner stress prior to childbirth (OR 3.92, 95% CI 1.08, 14.19), maternal education < 12 years (OR 2.69, 95% CI 1.24, 5.81), maternal substance use (OR 2.69, 95% CI 1.24, 5.81), younger maternal age (OR 0.87, 95% CI 0.80, 0.95), and a greater number of children (OR 1.62, 95% CI 1.09, 2.41) were associated with a higher likelihood of membership in a moderate risk/high protection class as compared to a low risk/moderate protection class. Conclusions: Results can inform eligibility criteria for prenatal home visiting programs and prenatal screening in Alaska to ensure prevention programming and referrals are directed to families most in need of additional support

Heterogeneity in Risk and Protection Among Alaska Native/American Indian and Non-Native Children

Currently, little is known about patterns of co-occurring risk and protective factors among young children. Understanding variations in co-occurring risk and protective factors among children in Alaska is important as experiences of collective trauma may contribute to differences in the intersection of risk and protective factors between Alaska Native/American Indian (AN/AI) and non-Native children. Using data from the Alaska Longitudinal Child Abuse and Neglect Linkage (ALCANLink) project, a linkage of the 2009–2011 Alaska Pregnancy Risk Assessment Monitoring System survey and administrative data sources, and the 2012–2014 Childhood Understanding Behaviors Survey, we conducted latent class analysis to identify classes of AN/AI (N = 593) and non-Native (N = 1018) children in terms of seven risk factors (poverty, maternal depression, maternal binge drinking, parental incarceration, intimate partner violence exposure, other violence exposure, child maltreatment) and four protective factors (father figure involvement, reading by adults, family meals, peer interactions) experienced prior to age 3 years. We identified two classes among AN/AI children: (1) high risk-moderate protection (29.1%) and (2) low socioeconomic status-high protection (70.9%). We identified two classes among non-Native children: (1) moderate risk-high protection (32.9%) and (2) low risk-high protection (67.1%). A test of invariance revealed that risk and protective factor probabilities differed significantly for corresponding classes of AN/AI and non-Native children. Overall, results demonstrate heterogeneity within and between AN/AI and non-Native children in early experiences of risk and protection and suggest that interventions will be more effective if tailored to the experiences and developmental needs of specific groups of Alaska children

Patterns of Risk and Protective Factors Among Alaska Children: Association With Maternal and Child Well-Being

This study used population-representative data to examine associations of risk and protective factor patterns among Alaska Native/American Indian (AN/AI; N = 592) and non-Native (N = 1,018) children with maternal and child outcomes at age 3 years. Among AN/AI children, a high risk/moderate protection class was associated with child developmental risk and mothers being less likely to feel comfortable asking for help or knowing where to go for parenting information compared to a low socioeconomic status/high protection class. Among non-Native children, a moderate risk/high protection class was associated with child developmental risk and mothers being less likely to feel comfortable asking for help compared to a low risk/high protection class. Results provide insight on the intersection of risk and protective factors among Alaska families

Soil nutrients and beta diversity in the Bornean Dipterocarpaceae: evidence for niche partitioning by tropical rain forest trees

1   The relative importance of niche- and dispersal-mediated processes in structuring diverse tropical plant communities remains poorly understood. Here, we link mesoscale beta diversity to soil variation throughout a lowland Bornean watershed underlain by alluvium, sedimentary and granite parent materials ( c . 340 ha, 8–200 m a.s.l.). We test the hypothesis that species turnover across the habitat gradient reflects interspecific partitioning of soil resources. 2   Floristic inventories (≥ 1 cm d.b.h.) of the Dipterocarpaceae, the dominant Bornean canopy tree family, were combined with extensive soil analyses in 30 (0.16 ha) plots. Six samples per plot were analysed for total C, N, P, K, Ca and Mg, exchangeable K, Ca and Mg, extractable P, texture, and pH. 3   Extractable P, exchangeable K, and total C, N and P varied significantly among substrates and were highest on alluvium. Thirty-one dipterocarp species ( n  = 2634 individuals, five genera) were recorded. Dipterocarp density was similar across substrates, but richness and diversity were highest on nutrient-poor granite and lowest on nutrient-rich alluvium. 4   Eighteen of 22 species were positively or negatively associated with parent material. In 8 of 16 abundant species, tree distribution (≥ 10 cm d.b.h.) was more strongly non-random than juveniles (1–10 cm d.b.h.), suggesting higher juvenile mortality in unsuitable habitats. The dominant species Dipterocarpus sublamellatus (> 50% of stems) was indifferent to substrate, but nine of 11 ‘subdominant’ species (> 8 individuals ha −1 ) were substrate specialists. 5   Eighteen of 22 species were significantly associated with soil nutrients, especially P, Mg and Ca. Floristic variation was significantly correlated with edaphic and geographical distance for all stems ≥ 1 cm d.b.h. in Mantel analyses. However, juvenile variation (1–10 cm d.b.h.) was more strongly related to geographical distance than edaphic factors, while the converse held for established trees (≥ 10 cm d.b.h.), suggesting increased importance of niche processes with size class. 6   Pervasive dipterocarp associations with soil factors suggest that niche partitioning structures dipterocarp tree communities. Yet, much floristic variation unrelated to soil was correlated with geographical distance between plots, suggesting that dispersal and niche processes jointly determine mesoscale beta diversity in the Bornean Dipterocarpaceae. Journal of Ecology (2005) doi: 10.1111/j.1365-2745.2005.01077.xPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72822/1/j.1365-2745.2005.01077.x.pd

CSF1R inhibitor JNJ-40346527 attenuates microglial proliferation and neurodegeneration in P301S mice.

Neuroinflammation and microglial activation are significant processes in Alzheimer's disease pathology. Recent genome-wide association studies have highlighted multiple immune-related genes in association with Alzheimer's disease, and experimental data have demonstrated microglial proliferation as a significant component of the neuropathology. In this study, we tested the efficacy of the selective CSF1R inhibitor JNJ-40346527 (JNJ-527) in the P301S mouse tauopathy model. We first demonstrated the anti-proliferative effects of JNJ-527 on microglia in the ME7 prion model, and its impact on the inflammatory profile, and provided potential CNS biomarkers for clinical investigation with the compound, including pharmacokinetic/pharmacodynamics and efficacy assessment by TSPO autoradiography and CSF proteomics. Then, we showed for the first time that blockade of microglial proliferation and modification of microglial phenotype leads to an attenuation of tau-induced neurodegeneration and results in functional improvement in P301S mice. Overall, this work strongly supports the potential for inhibition of CSF1R as a target for the treatment of Alzheimer's disease and other tau-mediated neurodegenerative diseases.Funded by a grant from the Wellcome Trust (Grant number: 104025/Z/14/Z), and by the NIHR Oxford Health Biomedical Research Centre

On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection

A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)