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The science of studying diamond inclusions for understanding Earth history has developed significantly over the past decades, with new instrumentation and techniques applied to diamond sample archives revealing the stories contained within diamond inclusions. This chapter reviews what diamonds can tell us about the deep carbon cycle over the course of Earth’s history. It reviews how the geochemistry of diamonds and their inclusions inform us about the deep carbon cycle, the origin of the diamonds in Earth’s mantle, and the evolution of diamonds through time.
Psychosocial interventions that mitigate psychosocial distress in cancer patients are important. The primary aim of this study was to examine the feasibility and acceptability of an adaptation of the Mindful Self-Compassion (MSC) program among adult cancer patients. A secondary aim was to examine pre–post-program changes in psychosocial wellbeing.
The research design was a feasibility and acceptability study, with an examination of pre- to post-intervention changes in psychosocial measures. A study information pack was posted to 173 adult cancer patients 6 months–5 years post-diagnosis, with an invitation to attend an eight-week group-based adaptation of the MSC program.
Thirty-two (19%) consented to the program, with 30 commencing. Twenty-seven completed the program (mean age: 62.93 years, SD 14.04; 17 [63%] female), attending a mean 6.93 (SD 1.11) group sessions. There were no significant differences in medico-demographic factors between program-completers and those who did not consent. However, there was a trend toward shorter time since diagnosis in the program-completers group. Program-completers rated the program highly regarding content, relevance to the concerns of cancer patients, and the likelihood of recommending the program to other cancer patients. Sixty-three percent perceived that their mental wellbeing had improved from pre- to post-program; none perceived a deterioration in mental wellbeing. Small-to-medium effects were observed for depressive symptoms, fear of cancer recurrence, stress, loneliness, body image satisfaction, mindfulness, and self-compassion.
Significance of results
The MSC program appears feasible and acceptable to adults diagnosed with non-advanced cancer. The preliminary estimates of effect sizes in this sample suggest that participation in the program was associated with improvements in psychosocial wellbeing. Collectively, these findings suggest that there may be value in conducting an adequately powered randomized controlled trial to determine the efficacy of the MSC program in enhancing the psychosocial wellbeing of cancer patients.
EPA and DHA are important components of cell membranes. Since humans have limited ability for EPA and DHA synthesis, these must be obtained from the diet, primarily from oily fish. Dietary EPA and DHA intakes are constrained by the size of fish stocks and by food choice. Seed oil from transgenic plants that synthesise EPA and DHA represents a potential alternative source of these fatty acids, but this has not been tested in humans. We hypothesised that incorporation of EPA and DHA into blood lipids from transgenic Camelina sativa seed oil (CSO) is equivalent to that from fish oil. Healthy men and women (18–30 years or 50–65 years) consumed 450 mg EPA + DHA from either CSO or commercial blended fish oil (BFO) in test meals in a double-blind, postprandial cross-over trial. There were no significant differences between test oils or sexes in EPA and DHA incorporation into plasma TAG, phosphatidylcholine or NEFA over 8 h. There were no significant differences between test oils, age groups or sexes in postprandial VLDL, LDL or HDL sizes or concentrations. There were no significant differences between test oils in postprandial plasma TNFα, IL 6 or 10, or soluble intercellular cell adhesion molecule-1 concentrations in younger participants. These findings show that incorporation into blood lipids of EPA and DHA consumed as CSO was equivalent to BFO and that such transgenic plant oils are a suitable dietary source of EPA and DHA in humans.
The experiences of police officers who have retired from the police service have rarely comprised the focus of empirical studies in England and Wales. Drawing on the findings of a survey of former police officers, this article examines the circumstances within which officers leave the service and aspects of the transition to retirement. We find that that certain individual, role and organisational factors come together to explain how the transition to retirement is experienced by police officers. We conceptualise police retirement as a multi-dimensional process during which a number of factors may come into play and have different effects depending on the circumstances in which retirement occurs. Findings are considered in light of wider conceptualisations of the process of retirement and implications are discussed.
Little is known about what motivates people to enroll in research registries. The purpose of this study is to identify facilitators of registry enrollment among diverse older adults.
Participants completed an 18-item Research Interest Assessment Tool. We used logistic regression analyses to examine responses across participants and by race and gender.
Participants (N=374) were 58% black, 76% women, with a mean age of 68.2 years. All participants were motivated to maintain their memory while aging. Facilitators of registry enrolled varied by both race and gender. Notably, blacks (estimate=0.71, p<0.0001) and women (estimate=0.32, p=0.03) were more willing to enroll in the registry due to home visits compared with whites and men, respectively.
Researchers must consider participant desire for maintaining memory while aging and home visits when designing culturally tailored registries.
The effect of folic acid (FA) on breast cancer (BC) risk is uncertain. We hypothesised that this uncertainty may be due, in part, to differential effects of FA between BC cells with different phenotypes. To test this we investigated the effect of treatment with FA concentrations within the range of unmetabolised FA reported in humans on the expression of the transcriptome of non-transformed (MCF10A) and cancerous (MCF7 and Hs578T) BC cells. The total number of transcripts altered was: MCF10A, seventy-five (seventy up-regulated); MCF7, twenty-four (fourteen up-regulated); and Hs578T, 328 (156 up-regulated). Only the cancer-associated gene TAGLN was altered by FA in all three cell lines. In MCF10A and Hs578T cells, FA treatment decreased pathways associated with apoptosis, cell death and senescence, but increased those associated with cell proliferation. The folate transporters SLC19A1, SLC46A1 and FOLR1 were differentially expressed between cell lines tested. However, the level of expression was not altered by FA treatment. These findings suggest that physiological concentrations of FA can induce cell type-specific changes in gene regulation in a manner that is consistent with proliferative phenotype. This has implications for understanding the role of FA in BC risk. In addition, these findings support the suggestion that differences in gene expression induced by FA may involve differential activities of folate transporters. Together these findings indicate the need for further studies of the effect of FA on BC.
Mounting an antibody response capable of discriminating amongst and appropriately targeting different parasites is crucial in host defence. However, cross-reactive antibodies that recognize (bind to) multiple parasite species are well documented. We aimed to determine if a higher inoculating dose of one species, and thus exposure to larger amounts of antigen over a longer period of time, would fine-tune responses to that species and reduce cross-reactivity. Using the Plasmodium chabaudi chabaudi (Pcc)–Nippostrongylus brasiliensis (Nb) co-infection model in BALB/c mice, in which we previously documented cross-reactive antibodies, we manipulated the inoculating dose of Pcc across 4 orders of magnitude. We investigated antigen-specific and cross-reactive antibody responses against crude and defined recombinant antigens by enzyme linked immunosorbent assay, Western blot and antibody depletion assays. Contrary to our hypothesis that increasing exposure to Pcc would reduce cross-reactivity to Nb, we found evidence for increased avidity of a subpopulation of antibodies that recognized shared antigens. Western blot indicated proteins of apparent monomer molecular mass 28 and 98 kDa in both Nb and Pcc antigen preparations and also an Nb protein of similar size to recombinant Pcc antigen, merozoite surface protein-119. The implications of antibodies binding antigen from such phylogenetically distinct parasites are discussed.
To identify the behavioral determinants—both barriers and enablers—that may impact physician hand hygiene compliance.
A qualitative study involving semistructured key informant interviews with staff physicians and residents.
An urban, 1,100-bed multisite tertiary care Canadian hospital.
A total of 42 staff physicians and residents in internal medicine and surgery.
Semistructured interviews were conducted using an interview guide that was based on the theoretical domains framework (TDF), a behavior change framework comprised of 14 theoretical domains that explain health-related behavior change. Interview transcripts were analyzed using thematic content analysis involving a systematic 3-step approach: coding, generation of specific beliefs, and identification of relevant TDF domains.
Similar determinants were reported by staff physicians and residents and between medicine and surgery. A total of 53 specific beliefs from 9 theoretical domains were identified as relevant to physician hand hygiene compliance. The 9 relevant domains were knowledge; skills; beliefs about capabilities; beliefs about consequences; goals; memory, attention, and decision processes; environmental context and resources; social professional role and identity; and social influences.
We identified several key determinants that physicians believe influence whether and when they practice hand hygiene at work. These beliefs identify potential individual, team, and organization targets for behavior change interventions to improve physician hand hygiene compliance.
Infect Control Hosp Epidemiol 2014;35(12):1511–1520
It is well established that genotype plays an important role in the ageing process. However, recent studies have suggested that epigenetic mechanisms may also influence the onset of ageing-associated diseases and longevity. Epigenetics is defined as processes that induce heritable changes in gene expression without a change in the DNA nucleotide sequence. The major epigenetic mechanisms are DNA methylation, histone modification and non-coding RNA. Such processes are involved in the regulation of tissue-specific gene expression, cell differentiation and genomic imprinting. However, epigenetic dysregulation is frequently seen with ageing. Relatively little is known about the factors that initiate such changes. However, there is emerging evidence that the early life environment, in particular nutrition, in early life can induce long-term changes in DNA methylation resulting in an altered susceptibility to a range of ageing-associated diseases. In this review, we will focus on the changes in DNA methylation that occur during ageing; their role in the ageing process and how early life nutrition can modulate DNA methylation and influence longevity. Understanding the mechanisms by which diet in early life can influence the epigenome will be crucial for the development of preventative and intervention strategies to increase well-being in later life.
It is uncertain whether antipsychotic long-acting injection (LAI) medication in schizophrenia is associated with better clinical outcomes than oral preparations.
To examine the impact of prior treatment delivery route on treatment outcomes and whether any differences are moderated by adherence.
Analysis of data from two pragmatic 1-year clinical trials in which patients with schizophrenia were randomised to either an oral first-generation antipsychotic (FGA), or a non-clozapine second-generation antipsychotic (SGA, CUtLASS 1 study), or a non-clozapine SGA or clozapine (CUtLASS 2 study).
Across both trials, 43% (n = 155) of participants were prescribed an FGA-LAI before randomisation. At 1-year follow-up they showed less improvement in quality of life, symptoms and global functioning than those randomised from oral medication. This difference was confined to patients rated as less than consistently adherent pre-randomisation. The relatively poor improvement in the patients prescribed an LAI pre-randomisation was ameliorated if they had been randomised to clozapine rather than another SGA. There was no advantage to being randomly assigned from an LAI at baseline to a non-clozapine oral SGA rather than an oral FGA.
A switch at randomisation from an LAI to an oral antipsychotic was associated with poorer clinical and functional outcomes at 1-year follow-up compared with switching from one oral antipsychotic to another. This effect appears to be moderated by adherence, and may not extend to switching to clozapine. This has implications for clinical trial design: the drug from which a participant is randomised may have a greater effect than the drug to which they are randomised.
In Canada and elsewhere, research policies require researchers to secure consent from a legally authorized representative (LAR) for prospective participants unable to consent. Few jurisdictions, however, offer a clear legislative basis for LAR identification. We investigated Canadian researchers’ practices regarding the involvement of decisionally incapacitated participants and tested whether reported practices were associated with (1) researchers’ understanding of the law on third-party authorization of research and (2) their comfort with allowing a family member to consent on behalf of an incapacitated relative.
We surveyed researchers in aging from four Canadian provinces about their practices with prospective participants deemed incapable of consent, their understanding of relevant law, and comfort with family consent for research purposes. Understanding and comfort were measured with research vignettes that briefly described hypothetical studies in which an adult who lacks the capacity to consent was invited to participate.
Many respondents reported soliciting consent from a family member (45.7% for low-risk studies and 10.7% for serious risks studies), even in jurisdictions where such authority is uncertain at law. Researchers’ tendency to solicit family consent was associated with their comfort in doing so, but not with their understanding of the law on substitute consent for research.
Findings underscore the need to clarify who may authorize an incapacitated adult's participation in research. Meanwhile, people should inform their relatives of their desire to participate or not in research in the event of incapacity, given researchers’ tendency to turn to family for consent, even where not supported by law.
Radiocarbon is present in solid radioactive wastes arising from the nuclear power industry, in reactor operating wastes, and in graphite and activated metals that will arise from reactor decommissioning. Its half-life of 5730 yr, among other factors, means that 14C may be released to the biosphere from radioactive waste repositories. These releases may occur as 14C-bearing gases, especially methane, or as aqueous species, and enter the biosphere from below via natural processes or via groundwater pumped from wells. Assessment of radiation doses to humans due to such releases must take account of the major role of carbon in biological processes, requiring specific 14C assessment models to be developed. Therefore, an intercomparison of 5 14C assessment models was organized by the international collaborative forum, BIOPROTA. The intercomparison identified significantly different results for the activity concentrations in the soil, atmosphere, and plant compartments, based upon the different modeling approaches. The major source of uncertainty was related to the identification of conditions under which mixing occurs and isotopic equilibrium is established. Furthermore, while the assumed release area plays a role in determining the calculated atmospheric 14C concentrations, the openness of the plant canopy and the wind profile in and above the canopy are the key drivers. The intercomparison has aided understanding of the processes involved and helped to identify areas where further research is required to address some of the uncertainties.
Maternal folic acid (FA) supplementation is well recognised to protect against neural tube defects. Folate is a critical cofactor in one-carbon metabolism involved in the epigenetic regulation of transcription that underpins development. Thus, it is possible that maternal FA supplementation may have additional, unforeseen persistent effects in the offspring. This is supported by the modification by maternal supplementation with one-carbon donors and FA of the epigenetic regulation of offspring phenotype in mutant mice. The present article reviews studies in human subjects and experimental animals of the effect of maternal FA intake and phenotypic outcomes in the offspring. Maternal FA intake was associated with a short-term increased incidence of allergy-related respiratory impairment in children and multigenerational respiratory impairment in rats. Higher maternal folate status during pregnancy was associated positively with insulin resistance in 6-year-olds. In rats, maternal FA supplementation modified hepatic metabolism and vascular function through altered transcription, in some cases underpinned by epigenetic changes. FA supplementation in pregnant rats increased mammary tumorigenesis, but decreased colorectal cancer in the offspring. Maternal FA supplementation decreased a range of congenital cardiac defects in children. These findings support the view that maternal FA supplementation induces persistent changes in a number of phenotypic outcomes in the offspring. However, the number of studies is limited and insufficient to indicate a need to change current recommendations for FA intake in pregnancy. Nevertheless, such effects should be investigated thoroughly in order to support firm conclusions about the risk of unanticipated long-term negative effects of maternal FA supplementation in humans.
Environmental exposures throughout the life course, including nutrition, may induce phenotypic and epigenetic changes. There is limited information about how timing affects the nature of such effects induced by a specific nutritional exposure. We investigated the effect of increased exposure to folic acid before birth or during the juvenile–pubertal period in rats on the epigenetic regulation of glucose homeostasis. Rats were fed either a folic acid-adequate (AF; 1 mg/kg feed) or a folic acid-supplemented (FS; 5 mg/kg feed) diet from conception until delivery and then an AF diet during lactation. Juvenile rats were fed either the AF or the FS diet from weaning for 28 d and then an AF diet. Liver and blood were collected after a 12 h fast between postnatal days 84 and 90. Maternal FS diet increased plasma glucose concentration significantly (P < 0·05) in females, but not in males. Post-weaning FS diet decreased glucose concentration significantly in females, but increased glucose concentration in males. There were no effects of the FS diet on phosphoenolpyruvate carboxykinase (PEPCK) mRNA expression in males, while the pattern of expression was related to plasma glucose concentration in females. The FS diet induced specific changes in the methylation of individual CpG in females, but not in males, which were related to the time of exposure. Methylation of CpG − 248 increased the binding of CCAAT-enhancer-binding protein β to the PEPCK promoter. Together, these findings show that both the period during the life course and sex influence the effect of increased exposure to folic acid on the epigenetic regulation of PEPCK and glucose homeostasis.
Alexander Litvinenko died on November 23, 2006, from acute radiation sickness syndrome caused by ingestion of polonium-210 (210Po).
The objective was to assess the prevalence of and risk factors for internal contamination with 210Po in healthcare workers (HCWs) caring for the contaminated patient.
HCWs who had direct contact with the patient.
We interviewed 43 HCWs and enquired about their activities and use of personal protective equipment (PPE). Internal contamination was denned as urinary 210Po excretion above 20 mBq within 24 hours. We obtained risk ratios (RRs) for internal contamination using Poisson regression.
Thirty-seven HCWs (86%) responded, and 8 (22%) showed evidence of internal contamination, all at very low levels that were unlikely to cause adverse health outcomes. Daily care of the patient (washing and toileting the patient) was the main risk factor (RR, 3.6 [95% confidence interval (CI), 1.1-11.6]). In contrast, planned invasive procedures were not associated with a higher risk. There was some evidence of a higher risk associated with handling blood samples (RR, 3.5 [95% CI, 0.8-15.6]) and changing urine bags and/or collecting urine samples (RR, 2.7 [95% CI, 0.8-9.5]). There was also some evidence that those who reported not always using standard PPE were at higher risk than were others (RR, 2.5 [95% CI, 0.8-8.1]).
The sensitive quantitative measurement enabled us to identify factors associated with contamination, which by analogy to other conditions with similar transmission mechanisms may help improve protection and preparedness in staff dealing with an ill patient who experiences an unknown illness.
Background: Dementia research often requires the participation of people with dementia. Obtaining informed consent is problematic when potential participants lack the capacity to provide it. We investigated comfort with proxy consent to research involving older adults deemed incapable of this decision, and examined if comfort varies with the type of proxy and the study's risk-benefit profile.
Methods: We surveyed random samples of five relevant groups (older adults, informal caregivers, physicians, researchers in aging, and Research Ethics Board members) from four Canadian provinces. Respondents were presented with scenarios involving four types of proxies (non-assigned, designated in a healthcare advance directive with or without instructions specific to research participation, and court-appointed). Given a series of risk-benefit profiles, respondents indicated whether they were comfortable with proxy consent to research for each scenario.
Results: Two percent of the respondents felt proxy consent should never be allowed. In all groups, comfort depended far more on the risk-benefit profile associated with the research scenario than with type of proxy. For research involving little or no risk and potential personal benefits, over 90% of the respondents felt comfortable with substitute consent by a designated or court-appointed proxy while 80% were at ease with a non-assigned proxy. For studies involving serious risks with potentially greater personal benefits, older adults and informal caregivers were less comfortable with proxy consent.
Conclusions: A large majority of Canadians are comfortable with proxy consent for low-risk research. Further work is needed to establish what kinds of research are considered to be low risk.