Mechanical properties of rapidly solidified Ni5Ge3 intermetallic

The congruently melting, single phase, intermetallic Ni5Ge3 has been subject to rapid solidification via drop-tube processing wherein powders with diameters between 850–150 μm are produced. At these cooling rates (850–150 μm diameter particles, 700–7800 K s−1) the dominant solidification morphology, revealed after etching, is that of isolated plate and lath microstructure in an otherwise featureless matrix. Selected area diffraction analysis in the TEM reveals the plate and lath are a disordered variant of ε-Ni5Ge3, whilst the featureless matrix is the ordered variant of the same compound. Microvicker hardness test result shows that mechanical properties improve with decreasing the particle size from 850 to 150 μm as a consequence of increasing the cooling rate

Morphology of order-disorder structures in rapidly solidified L12 intermetallics

Utilization of intermetallics in high temperature applications is limited due to their poor room temperature ductility. One route to overcoming this is disorder trapping (and subsequent anti-phase domain formation) during rapid solidification, motivating the study of disorder trapping in intermetallics. The single-phase, L1₂ intermetallic beta-Ni₃Ge has been rapidly solidified via drop-tube processing. At low cooling rates (850 – 500 um diameter particles, 700 – 2800 K/s) the dominant solidification morphology, revealed after etching, is that of isolated spherulites in an otherwise featureless matrix. Selected area diffraction analysis in the TEM reveals the spherulites to be partially disordered beta-Ni₃Ge, whilst the featureless matrix is the fully ordered variant of the same compound. Dark-field TEM imaging has confirmed that the spherulites grow as radially emanating fingers of the ordered phase, with disordered material in the space between the fingers

Disorder-order morphologies in drop-tube processed Ni3Ge: Dendritic and seaweed growth

The single phase intermetallic β-Ni3Ge has been subject to rapid solidification via drop-tube processing. Droplets spanning the size range 212–38 μm, with corresponding cooling rates of 5800–54,500 K s−1, have been subject to microstructural investigation using SEM. Three dominant solidification morphologies have been identified with increasing cooling rate, namely; (i) well-defined dendrites with orthogonal side-branching, (ii) dendrites with non-orthogonal side-branching and (iii) dendritic seaweed. Selected area diffraction analysis in the TEM reveals that both types of dendrites are the disordered form of β-Ni3Ge in a matrix of the ordered, L12, form. However, the diffraction pattern from the dendritic seaweed cannot be mapped onto a cubic structure, indicating a change in the underlying crystallography coincident with the transition to the seaweed structure

The Role of Recrystallization in Spontaneous Grain Refinement of Rapidly Solidified Ni₃Ge

The congruently melting intermetallic β-Ni₃Ge has been subject to rapid solidification via drop-tube processing. Droplets spanning the size range 75 to 53 μm, with corresponding cooling rates of 23,000 to 42,000 K s−1, have been found to undergo spontaneous grain refinement by recrystallization and recovery. Outside of this relatively narrow size range, the primary solidification morphology is retained, either dendritic for larger particles or dendritic seaweed for smaller particles

Individual and group based parenting programmes for improving psychosocial outcomes for teenage parents and their children.

BACKGROUND: Parenting programmes are a potentially important means of supporting teenage parents and improving outcomes for their children, and parenting support is a priority across most Western countries. This review updates the previous version published in 2001. OBJECTIVES: To examine the effectiveness of parenting programmes in improving psychosocial outcomes for teenage parents and developmental outcomes in their children. SEARCH STRATEGY: We searched to find new studies for this updated review in January 2008 and May 2010 in CENTRAL, MEDLINE, EMBASE, ASSIA, CINAHL, DARE, ERIC, PsycINFO, Sociological Abstracts and Social Science Citation Index. The National Research Register (NRR) was last searched in May 2005 and UK Clinical Research Network Portfolio Database in May 2010. SELECTION CRITERIA: Randomised controlled trials assessing short-term parenting interventions aimed specifically at teenage parents and a control group (no-treatment, waiting list or treatment-as-usual). DATA COLLECTION AND ANALYSIS: We assessed the risk of bias in each study. We standardised the treatment effect for each outcome in each study by dividing the mean difference in post-intervention scores between the intervention and control groups by the pooled standard deviation. MAIN RESULTS: We included eight studies with 513 participants, providing a total of 47 comparisons of outcome between intervention and control conditions. Nineteen comparisons were statistically significant, all favouring the intervention group. We conducted nine meta-analyses using data from four studies in total (each meta-analysis included data from two studies). Four meta-analyses showed statistically significant findings favouring the intervention group for the following outcomes: parent responsiveness to the child post-intervention (SMD -0.91, 95% CI -1.52 to -0.30, P = 0.04); infant responsiveness to mother at follow-up (SMD -0.65, 95% CI -1.25 to -0.06, P = 0.03); and an overall measure of parent-child interactions post-intervention (SMD -0.71, 95% CI -1.31 to -0.11, P = 0.02), and at follow-up (SMD -0.90, 95% CI -1.51 to -0.30, P = 0.004). The results of the remaining five meta-analyses were inconclusive. AUTHORS' CONCLUSIONS: Variation in the measures used, the included populations and interventions, and the risk of bias within the included studies limit the conclusions that can be reached. The findings provide some evidence to suggest that parenting programmes may be effective in improving a number of aspects of parent-child interaction both in the short- and long-term, but further research is now needed

No dependence of radio properties of brightest group galaxies on the luminosity gap

We study the radio and optical properties of the brightest group galaxies (BGGs) in a sample of galaxy groups from the SDSS DR7. The luminosity difference between the BGG and the second ranked galaxy in the group (known as the luminosity, or magnitude, gap) has been used as a probe for the level of galaxy interaction for the BGG within the group. We study the properties of BGGs with magnitude gaps in the range 0-2.7 magnitudes, in order to investigate any relation between luminosity gap and the radio properties of the BGG. In order to eliminate selection biases, we ensure that all variations in stellar mass are accounted for. We then confirm that, at fixed stellar mass, there are no significant variations in the optical properties of the BGGs over the full range of luminosity gaps studied. We compare these optical results with the EAGLE hydrodynamical simulations and find broad consistency with the observational data. Using EAGLE we also confirm that no trends begin to arise in the simulated data at luminosity gaps beyond our observational limits. Finally, we find that, at fixed stellar mass, the fraction of BGGs that are radio-loud also shows no trends as a function of luminosity gap. We examine how the BGG offset from the center of group may affect the radio results and find no significant trend for the fraction of radio-loud BGGs with magnitude gap in either the BGG samples with greater or less than 100kpc offset from the center of group.Comment: Accepted for publication in A

Loss of miR-200c: A Marker of Aggressiveness and Chemoresistance in Female Reproductive Cancers

We focus on unique roles of miR-200c in breast, ovarian, and endometrial cancers. Members of the miR-200 family target ZEB1, a transcription factor which represses E-cadherin and other genes involved in polarity. We demonstrate that the double negative feedback loop between miR-200c and ZEB1 is functional in some, but not all cell lines. Restoration of miR-200c to aggressive cancer cells causes a decrease in migration and invasion. These effects are independent of E-cadherin status. Additionally, we observe that restoration of miR-200c to ovarian cancer cells causes a decrease in adhesion to laminin. We have previously reported that reintroduction of miR-200c to aggressive cells that lack miR-200c expression restores sensitivity to paclitaxel. We now prove that this ability is a result of direct targeting of class III beta-tubulin (TUBB3). Introduction of a TUBB3 expression construct lacking the miR-200c target site into cells transfected with miR-200c mimic results in no change in sensitivity to paclitaxel. Lastly, we observe a decrease in proliferation in cells transfected with miR-200c mimic, and cells where ZEB1 is knocked down stably, demonstrating that the ability of miR-200c to enhance sensitivity to paclitaxel is not due to an increased proliferation rate

Aboriginal and Non-Aboriginal Students Learn About Natural Health Products from Different Information Sources

Natural health products (NHPs) include naturally derived botanical and nonbotanical products. Past research indicates a high prevalence of NHPs use amongst adults in the United States and Canada but does not clearly characterize NHPs use amongst students, ethnic variations of such use, or how users learn about NHPs. We hypothesize that there is a difference between Aboriginal and non-Aboriginal students in how they learn about NHPs. To investigate this question, we conducted a cross-sectional study at First Nations University of Canada and the University of Regina, Saskatchewan, Canada, during the fall of 2011. Aboriginal (n=214) and non-Aboriginal (n=749) students participated in the 28 question survey. Our results indicate that Aboriginal students who use NHPs are found in all age groups, are mostly female, are smokers and nonsmokers, and learn about NHPs from Elders and healers. Compared to nonAboriginal students, Aboriginal students rely significantly less on alternative and conventional health providers, electronic media, print media, and advertising as their sources of information about NHPs. Thus, Aboriginal students use Elders or healers as a primary source of information to learn about NHPs, as compared to non-Aboriginal students. Future work should investigate the role of Elder traditional educators to convey NHPs information directed specifically to Aboriginal university students