Physico-chemical and thermochemical studies of the hydrolytic conversion of amorphous tricalcium phosphate into apatite

The conversion of amorphous tricalcium phosphate with different hydration ratio into apatite in water at 25 °C has been studied by microcalorimetry and several physical–chemical methods. The hydrolytic transformation was dominated by two strong exothermic events. A fast, relatively weak, wetting process and a very slow but strong heat release assigned to a slow internal rehydration and the crystallization of the amorphous phase into an apatite. The exothermic phenomenon related to the rehydration exceeded the crystalline transformation enthalpy. Rehydration occurred before the conversion of the amorphous phase into apatite and determined the advancement of the hydrolytic reaction. The apatitic phases formed evolved slightly with time after their formation. The crystallinity increased whereas the amount of HPO4 2− ion decreased. These data allow a better understanding of the behavior of biomaterials involving amorphous phases such as hydroxyapatite plasma-sprayed coating

Nature-inspired calcium phosphate coatings : present status and novel advances in the science of mimicry

There has been a growing awareness in materials science that the adaptation of nature biological processes can lead to significant progresses in the controlled fabrication of advanced materials for an all range of applications. To learn from, understand and apply these natural processes for producing calcium phosphate coatings that are biologically similar to bone apatite, mimicking its properties, has driven the attention of many researchers in recent years. This article reviews the most relevant advances in this emerging research field, pointing out several approaches being introduced and explored by distinct laboratories

Enhancing Social-Emotional Outcomes in Early Years (E-SEE): Randomized Pilot Study of Incredible Years Infant and Toddler Programs

Abstract: Social emotional development in infancy is a predictor of outcomes in later life, yet there is little evidence of effectiveness for parenting interventions designed to enhance social emotional wellbeing in infancy. An 18-month two-arm randomized controlled pilot trial evaluated the feasibility of a definitive trial of Incredible Years (IY) Infant and Toddler parent programs delivered in a proportionate universal model, called Enhancing Social-Emotional Health and Wellbeing in the Early Years (E-SEE) Steps. Intervention families received an IY Babies book (universal dose), followed by the IY Infant and/or the Toddler group-based programs, based on parent depression (PHQ-9) and/or child social emotional development (ASQ:SE-2) scores. Control parents received services as usual. Parents from two English local authorities with a child eight-weeks-old or younger participated, and were block randomized using a web-based system. Primary endpoints for the study were feasibility parameters relating to recruitment, retention, intervention fidelity and appropriateness of measures. 205 participants were randomized (152:53, intervention:control). Our target was 288 parents. Trial retention rate was higher than expected, with a completion rate of 88% (n = 181, 137:44) at follow-up 3; equating to 94% of 192 expected participants. Intervention uptake was lower than expected. Fidelity of delivery was acceptable and measures were deemed appropriate. A definitive trial is feasible with design amendments to include: introduction of a child screener for intervention eligibility; enhanced intervention material; revised sample size and random allocation ratio. Our internal pilot became an external pilot due to these changes

Manganese in the shell of the bivalve Mytilus edulis: Seawater Mn or physiological control?

Manganese in the shell calcite of marine bivalves has been suggested to reflect ambient seawater Mn concentrations, thus providing a high-resolution archive of past seawater Mn concentrations. However, a quantitative relationship between seawater Mn and shell Mn/Ca ratios, as well as clear understanding of which process(es) control(s) shell Mn/Ca, are still lacking. Blue mussels, Mytilus edulis, were grown in a one-year duration field experiment in the Menai Strait, U.K., to study the relationship between seawater particulate and dissolved Mn2+ concentrations and shell calcite Mn/Ca ratios. Shell Mn/Ca showed a well-defined intra-annual double-peak, with maximum values during early spring and early summer and low values during autumn and winter. Seawater particulate Mn peaked during winter and autumn, with a series of smaller peaks during spring and summer, whereas dissolved Mn2+ exhibited a marked single maximum during late-spring to early-summer, being low during the remainder of the year. Consequently, neither seawater particulate Mn nor dissolved Mn2+ concentrations explain the intra-annual variation of shell Mn/Ca ratios. A physiological control on shell Mn/Ca ratios is evident from the strong similarity and timing of the double-peaked intra-annual variations of Mn/Ca and shell growth rate (SGR), the latter corresponding to periods of increased metabolic activity (as indicated by respiration rate). It is thus likely that in M. edulis SGR influences shell Mn/Ca by altering the concentration or activity of Mn2+ within the extra-pallial fluid (EPF), by changing the flux of Mn into or the proportion of protein bound Mn within the EPF. By linking shell Mn/Ca ratios to the endogenous and environmental factors that determine growth and metabolic activity, this study helps to explain the lack of a consistent relationship between shell Mn/Ca in marine bivalve shell calcite and seawater particulate and dissolved Mn2+ concentrations. The use of Mn content from M. edulis shell calcite as a proxy for the dissolved and/or particulate Mn concentrations, and thus the biogeochemical processes that control them, remains elusive

Results of the First Steps study: a randomised controlled trial and economic evaluation of the Group Family Nurse Partnership (gFNP) programme compared with usual care in improving outcomes for high-risk mothers and their children and preventing abuse

Background: Family Nurse Partnership (FNP) is a home-based nurse home-visiting programme to support vulnerable parents. Group Family Nurse Partnership (gFNP) has similar aims and materials and was demonstrated to be feasible in implementation evaluations. Objectives: To determine whether or not gFNP, compared with usual care, could reduce risk factors for maltreatment in a vulnerable group and be cost-effective. Design: A multisite randomised controlled parallel-group trial and prospective economic evaluation, with eligible women allocated (minimised by site and maternal age group) to gFNP or usual care. Setting: Community locations in the UK. Participants: Expectant mothers aged < 20 years with one or more previous live births, or expectant mothers aged 20–24 years with no previous live births and with low educational qualifications (defined as General Certificate of Education at grade C or higher in neither mathematics nor English language or, if they had both, no more than four General Certificates of Education at grade C or higher). Intervention: Forty-four sessions of gFNP (14 during pregnancy and 30 in the first 12 months after birth) were offered to groups of between 8 and 12 women with similar expected delivery dates (the difference between the earliest and latest expected delivery date ranged from 8 to 10 weeks depending on the group) by two family nurses (FNs), one of whom had notified her intention to practise as a midwife. Main outcome measures: Parenting was assessed by a self-report measure of parenting opinions, the Adult Adolescent Parenting Inventory Version 2 (AAPI-2), and an objective measure of maternal sensitivity, the CARE-Index. Cost-effectiveness was primarily expressed in terms of incremental cost per quality-adjusted life-year (QALY) gained. Data sources: Interviews with participants at baseline and when infants were aged 2, 6 and 12 months. Cost information from nurse weekly logs and other service delivery data. Results: In total, 166 women were enrolled (99 to the intervention group and 67 to the control group). Adjusting for site and maternal age group, the intention-to-treat analysis found no effect of gFNP on either of the primary outcomes. AAPI-2 total was 7.5/10 [standard error (SE) 0.1] in both arms [difference also adjusted for baseline 0.08, 95% confidence interval (CI) –0.15 to 0.28; p = 0.50]. CARE-Index maternal sensitivity mean: intervention 4.0 (SE 0.3); control 4.7 (SE 0.4) (difference –0.76, 95% CI –1.67 to 0.13; p = 0.21). The sensitivity analyses supported the primary analyses. The probability that the gFNP intervention was cost-effective based on the QALY measure did not exceed 3%. However, in terms of change in AAPI-2 score (baseline to 12 months), the probability that gFNP was cost-effective reached 25.1%. A separate discrete choice experiment highlighted the value placed by both pregnant women and members of the general population on non-health outcomes that were not included in the QALY metric. Limitations: Slow recruitment resulted in smaller than ideal group sizes. In some cases, few or no sessions took place owing to low initial group size, and small groups may have contributed to attrition from the intervention. Exposure to gFNP sessions was below maximum for most group members, with only 58 of the 97 intervention participants receiving any sessions; FNs were experienced with FNP but were mainly new to delivering gFNP. Conclusions: The trial does not support the delivery of gFNP as a means of reducing the risk of child abuse or neglect in this population. Future work: A randomised controlled trial with modified eligibility to enable first-time mothers aged < 20 years to be included, and a modified recruitment strategy to enable faster identification of potential participants from antenatal medical records

The Biology and Economics of Coral Growth

To protect natural coral reefs, it is of utmost importance to understand how the growth of the main reef-building organisms—the zooxanthellate scleractinian corals—is controlled. Understanding coral growth is also relevant for coral aquaculture, which is a rapidly developing business. This review paper provides a comprehensive overview of factors that can influence the growth of zooxanthellate scleractinian corals, with particular emphasis on interactions between these factors. Furthermore, the kinetic principles underlying coral growth are discussed. The reviewed information is put into an economic perspective by making an estimation of the costs of coral aquaculture

Promoting learning from null or negative results in prevention science trials

This is the final version. Available on open access from Springer via the DOI in this recordThere can be a tendency for investigators to disregard or explain away null or negative results in prevention science trials. Examples include not publicizing findings, conducting spurious subgroup analyses, or attributing the outcome post hoc to real or perceived weaknesses in trial design or intervention implementation. This is unhelpful for several reasons, not least that it skews the evidence base, contributes to research "waste", undermines respect for science, and stifles creativity in intervention development. In this paper, we identify possible policy and practice responses when interventions have null (ineffective) or negative (harmful) results, and argue that these are influenced by: the intervention itself (e.g., stage of gestation, perceived importance); trial design, conduct, and results (e.g., pattern of null/negative effects, internal and external validity); context (e.g., wider evidence base, state of policy); and individual perspectives and interests (e.g., stake in the intervention). We advance several strategies to promote more informative null or negative effect trials and enable learning from such results, focusing on changes to culture, process, intervention design, trial design, and environment.National Institute for Health Research (NIHR

Growth-rate dependence of Sr incorporation during calcification of Emiliania huxleyi

Reconstructing the dissolved carbon dioxide of surface waters from the δ13C of organic carbon relies on accurate determination of the growth rate of phytoplankton contributing to sedimentary organic matter. We demonstrate that the Sr/Ca ratio in the coccoliths of Emiliania huxleyi is correlated with the rates of both organic carbon fixation and calcification. An investigation of biomineralization models suggests that these three factors may be linked by the differential pumping rates of calcium relative to strontium ions across the cellular membranes which supply ions for photosynthetic carbon fixation and calcification and derives energy from photosynthetic products. A quantitative relationship is derived between calcification, organic carbon fixation, and Sr/Ca such that a combined geochemical proxy approach using εp and Sr/Ca can be applied to the paleoceanographic record