To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
L-citrulline may improve non-invasive vascular function and cardiometabolic risk markers through increases in L-arginine bioavailability and nitric oxide synthesis. A meta-analysis of randomized controlled trials (RCTs) was performed to examine longer-term and postprandial effects of L-citrulline supplementation and watermelon consumption on these markers for cardiovascular disease in adults. Summary estimates of weighted mean differences (WMDs) in vascular function and cardiometabolic risk markers with accompanying 95% confidence intervals (CIs) were calculated using random or fixed-effect meta-analyses. Seventeen RCTs were included involving an L-citrulline intervention, of which six studied postprandial and twelve longer-term effects. Five studies investigated longer-term effects of watermelon consumption and five assessed effects during the postprandial phase. Longer-term L-citrulline supplementation improved brachial artery flow-mediated vasodilation (FMD) by 0.9 %-point (95 % CI: 0.7 to 1.1, P < 0.001). Longer-term watermelon consumption improved pulse wave velocity by 0.9 m/s (95% CI: 0.1 to 1.5, P < 0.001), while effects on FMD were not studied. No postprandial effects on vascular function markers were found. Postprandial glucose concentrations decreased by 0.6 mmol/L (95% CI: 0.4 to 0.7, P < 0.001) following watermelon consumption, but no other longer-term or postprandial effects were observed on cardiometabolic risk markers. To conclude, longer-term L-citrulline supplementation and watermelon consumption may improve vascular function, suggesting a potential mechanism by which increased L-citrulline intake beneficially affects cardiovascular health outcomes in adults. No effects on postprandial vascular function markers were found, while more research is needed to investigate effects of L-citrulline and watermelon on risk markers related to cardiometabolic health.
Adolescent mental health difficulties are increasing over time. However, it is not known whether their adulthood health and socio-economic sequelae are changing over time.
Participants (N = 31 349) are from two prospective national birth cohort studies: 1958 National Child Development Study (n = 16 091) and the 1970 British Cohort Study (n = 15 258). Adolescent mental health was operationalised both as traditional internalising and externalising factors and a hierarchical bi-factor. Associations between adolescent psychopathology and age 42 health and wellbeing (mental health, general health, life satisfaction), social (cohabitation, voting behaviour) and economic (education and employment) outcomes are estimated using linear and logistic multivariable regressions across cohorts, controlling for a wide range of early life potential confounding factors.
The prevalence of adolescent mental health difficulties increased and their associations with midlife health, wellbeing, social and economic outcomes became more severe or remained similar between those born in 1958 and 1970. For instance, a stronger association with adolescent mental health difficulties was found for those born in 1970 for midlife psychological distress [odds ratio (OR) 1970 = 1.82 (1.65–1.99), OR 1958 = 1.60 (1.43–1.79)], cohabitation [OR 1970 = 0.64 (0.59–0.70), OR 1958 = 0.79 (0.72–0.87)], and professional occupations [OR 1970 = 0.75 (0.67–0.84), OR 1958 = 1.05 (0.88–1.24)]. The associations of externalising symptoms with later outcomes were mainly explained by their shared variance with internalising symptoms.
The widening of mental health-based inequalities in midlife outcomes further supports the need to recognise that secular increases in adolescent mental health symptoms is a public health challenge with measurable negative consequences through the life-course. Increased public health efforts to minimise adverse outcomes are needed.
Public involvement in service change has been identified as a key facilitator of health care transformation (Foley et al., 2017) but little is known about how health policy influences whether and how organisations involve the public in change processes. This qualitative study compares policy and practice for involving the public in major service changes across the UK's four health systems (England, Northern Ireland, Wales and Scotland). We analysed policy documents, and conducted interviews with officials, stakeholders, NHS staff and public campaigners (total number of interviewees = 47). Involving the public in major service change was acknowledged as a policy challenge in all four systems. Despite ostensible similarities, there were some clear differences between the four health systems' processes for involving patients and the public in major changes to health services. The extent of central Government oversight, the prescriptiveness of Government guidance, the role for intermediary bodies and arrangements for independent scrutiny of contentious decisions all vary. We analyse how health policy in the four systems has used ‘sticks’ and ‘sermons’ to promote particular approaches, and conclude that both policy and the wider system context within which health care organisations try to effect change are significant, and understudied aspect of contemporary practice.
Silver nanowire (AgNW) diameters are typically characterized by manual measurement from high magnification electron microscope images. Measurement is monotonous and has potential ergonomic hazards. Because of this, statistics regarding wire diameter distribution can be poor, costly, and low-throughput. In addition, manual measurements are of unknown uncertainty and operator bias. In this paper we report an improved microscopy method for diameter and yield measurement of nanowires in terms of speed/automation and reduction of analyst variability. Each step in the process to generate these measurements was analyzed and optimized: microscope imaging conditions, sample preparation for imaging, image acquisition, image analysis, and data processing. With the resulting method, average diameter differences between samples of just a few nanometers can be confidently and statistically distinguished, allowing the identification of subtle incremental improvements in reactor processing conditions, and insight into nucleation and growth kinetics of AgNWs.
Graphene oxide (GO)/MnO2 nanocomposites were synthesized by adding KMnO4 in a solution of water and ethanol (3:1), containing 10 mg of GO. Brown precipitates were obtained after a continuous stirring for 1 hr. The precipitates were then washed with deionized water (DI) water and dried to obtain the MnO2-GO nanocomposites. Pure MnO2 was also synthesized using the same method without GO for the comparison. X-ray diffraction pattern confirm δ-MnO2 type of MnO2 with birnessite type MnO2 structure. The TEM images show the average diameter of MnO2 nanorods as 15 nm. Electrochemical characterizations were carried out in an aqueous solution of 3M KOH. Charge-discharge studies were carried out between 1A/g to 20 A/g current range. The MnO2-GO nanocomposites showed improved electrochemical performances. The capacitance of MnO2 and MnO2-GO electrodes was found to be as 300 F/g, and 350 F/g, respectively at a current of 0.5 A/g.
The patterns of comorbidity among mental disorders have led researchers to model the underlying structure of psychopathology. While studies have suggested a structure including internalizing and externalizing disorders, less is known with regard to the cross-national stability of this model. Moreover, little data are available on the placement of eating disorders, bipolar disorder and psychotic experiences (PEs) in this structure.
We evaluated the structure of mental disorders with data from the World Health Organization Composite International Diagnostic Interview, including 15 lifetime mental disorders and six PEs. Respondents (n = 5478–15 499) were included from 10 high-, middle- and lower middle-income countries across the world aged 18 years or older. Confirmatory factor analyses (CFAs) were used to evaluate and compare the fit of different factor structures to the lifetime disorder data. Measurement invariance was evaluated with multigroup CFA (MG-CFA).
A second-order model with internalizing and externalizing factors and fear and distress subfactors best described the structure of common mental disorders. MG-CFA showed that this model was stable across countries. Of the uncommon disorders, bipolar disorder and eating disorder were best grouped with the internalizing factor, and PEs with a separate factor.
These results indicate that cross-national patterns of lifetime common mental-disorder comorbidity can be explained with a second-order underlying structure that is stable across countries and can be extended to also cover less common mental disorders.
Can we educate decision-makers to make better decisions? In the present paper, I argue that we can in at least two broad ways: (1) teaching concrete knowledge about a specific decision or decision type; and (2) teaching more abstract decision-making competencies that are thought to lead to better decisions. Teaching knowledge can be done using decision aids and similar techniques that provide important information about a specific choice (e.g. a medical treatment option). In these cases, information presented using evidence-based techniques to improve comprehension and use of information will have greater effects on judgements and choices. Teaching more abstract decision competencies, on the other hand, involves formal schooling (with the bulk of formal education falling during childhood) or training in a specific competency that is important to decision processes and outcomes; I use numeracy interventions as an exemplar.
Why does public conflict over societal risks persist in the face of compelling and widely accessible scientific evidence? We conducted an experiment to probe two alternative answers: the ‘science comprehension thesis’ (SCT), which identifies defects in the public's knowledge and reasoning capacities as the source of such controversies; and the ‘identity-protective cognition thesis’ (ICT), which treats cultural conflict as disabling the faculties that members of the public use to make sense of decision-relevant science. In our experiment, we presented subjects with a difficult problem that turned on their ability to draw valid causal inferences from empirical data. As expected, subjects highest in numeracy – a measure of the ability and disposition to make use of quantitative information – did substantially better than less numerate ones when the data were presented as results from a study of a new skin rash treatment. Also as expected, subjects’ responses became politically polarized – and even less accurate – when the same data were presented as results from the study of a gun control ban. But contrary to the prediction of SCT, such polarization did not abate among subjects highest in numeracy; instead, it increased. This outcome supported ICT, which predicted that more numerate subjects would use their quantitative-reasoning capacity selectively to conform their interpretation of the data to the result most consistent with their political outlooks. We discuss the theoretical and practical significance of these findings.
Depressive symptoms are common in amnestic mild cognitive impairment (aMCI). The association between depressive symptoms and conversion to dementia is not yet clear. This longitudinal study was conducted to ascertain whether depressive symptoms in aMCI patients are predictive of conversion to dementia.
35 aMCI patients participated in this study. All participants underwent cognitive testing and were administered the geriatric depression scale (GDS) to determine the presence of depressive symptoms. A score equaling or higher than 11 on the GDS was taken as the cut-off point for presence of significant depressive symptoms. Conversion to dementia was assessed at follow-up visits after 1.5, 4, and 10 years.
31.4% of the patients reported depressive symptoms at baseline. None of the cognitive measures revealed a significant difference at baseline between patients with and without depressive symptoms. After 1.5, 4, and 10 years respectively 6, 14, and 23 patients had converted to dementia. Although the GDS scores at baseline did not predict conversion to dementia, the cognitive measures and more specifically a verbal cued recall task (the memory impairment scale-plus) was a good predictor for conversion.
Based on this dataset, the presence of depressive symptoms in aMCI patients is not predictive of conversion to dementia.
Epidemiological evidence regarding the association between carbohydrate intake, glycaemic load (GL) and glycaemic index (GI) and risk of ovarian cancer has been mixed. Little is known about their impact on ovarian cancer risk in African-American women. Associations between carbohydrate quantity and quality and ovarian cancer risk were investigated among 406 cases and 609 controls using data from the African American Cancer Epidemiology Study (AACES). AACES is an ongoing population-based case–control study of ovarian cancer in African-Americans in the USA. Cases were identified through rapid case ascertainment and age- and site-matched controls were identified by random-digit dialling. Dietary information over the year preceding diagnosis or the reference date was obtained using a FFQ. Multivariable logistic regression models were used to estimate odds ratios and 95 % CI adjusted for covariates. The OR comparing the highest quartile of total carbohydrate intake and total sugar intake v. the lowest quartile were 1·57 (95 % CI 1·08, 2·28; Ptrend=0·03) and 1·61 (95 % CI 1·12, 2·30; Ptrend<0·01), respectively. A suggestion of an inverse association was found for fibre intake. Higher GL was positively associated with the risk of ovarian cancer (OR 1·18 for each 10 units/4184 kJ (1000 kcal); 95 % CI 1·04, 1·33). No associations were observed for starch or GI. Our findings suggest that high intake of total sugars and GL are associated with greater risk of ovarian cancer in African-American women.
Migratory fishes are natural wonders. For many people, the term migratory fish evokes images of salmon audaciously jumping at waterfalls as they return to their own riverine birthplace to spawn after years of growth in the ocean, but freshwater fishes actually show a broad spectrum of migration strategies. Migratory fishes include small species – three-spined sticklebacks that spawn in coastal streams around the northern Pacific and gobies that move from the ocean into tropical island streams by climbing waterfalls (McDowall, 1988) – as well as some of the largest freshwater fishes in the world, such as the Mekong dog-eating catfish and the Chinese paddlefish (Stone, 2007). Aside from migratory habits, these species have few shared characteristics; they encompass numerous evolutionary lineages, enormous differences in life history, and every possible direction and distance of migration. Biologists treat migratory freshwater fishes as a functional group because their life-history strategy revolves around long-distance movement between ecosystems in a perilous quest to take advantage of both high-quality breeding sites and bountiful feeding areas. As humans have physically blocked fish migrations, degraded breeding and feeding grounds and relentlessly harvested migrants for their flesh and roe, many populations have declined or been extirpated. This chapter will provide an overview of fundamental and applied research that is helping to guide efforts to conserve migratory freshwater fishes.
For practical purposes, we define migratory behaviour as the synchronized movement of a substantial proportion of a population between distinct habitats, which is repeated through time within or across generations. Modern definitions of fish migrations typically recognise both the adaptive benefits of migrating and individual variation in executing the general strategy (see McDowall, 1988; Lucas & Baras, 2001). Not every individual must move, the timing may vary somewhat from year to year, and the motive for migrating may include seeking refuge from harsh conditions in addition to breeding and feeding. Nonetheless, in most cases, migration is critical to individual fitness and population persistence because it enables specialised use of different habitats for growth and reproduction. Where their migration routes are blocked or key habitats are lost, migratory fishes often suffer rapid and catastrophic losses.
Human appropriation and degradation of the Earth's freshwater ecosystems (Vörösmarty et al., 2010; Carpenter et al., 2011) have transformed this reliance on multiple habitats into a detriment for many migratory fishes.
In the present study, we aimed to describe dietary changes made post-diagnosis and current dietary supplement use by survivors of colorectal cancer (CRC), and explore the underlying motives for these lifestyle habits. Cross-sectional analyses were performed for 1458 stage I–IV CRC survivors of the Patient Reported Outcomes Following Initial Treatment and Long-Term Evaluation of Survivorship (PROFILES) registry, diagnosed between 2000 and 2009. Lifestyle, sociodemographic and clinical information was collected. Prevalence of and motivations for dietary changes and supplement use were assessed. Associations between lifestyle, sociodemographic and clinical variables were analysed by multivariable logistic regression. CRC survivors (57 % male) were on average 70 (sd 9) years of age and diagnosed 7 (sd 3) years ago. Dietary changes post-diagnosis were reported by 36 % of the survivors and current supplement use by 32 %. Motivations for dietary changes were mostly cancer-related (44 % reported ‘prevention of cancer recurrence’ as the main reason), while motivations for supplement use were less frequently related to the cancer experience (38 % reported ‘to improve health and prevent disease in general’ as the main reason). Dietary changes were significantly associated with dietary supplement use (OR 1·5, 95 % CI 1·1, 2·1). Survivors who had received dietary advice, were non-smokers, under 65 years of age, and had no stoma were more likely to have changed their diet. Survivors who were female, had multiple co-morbidities, and no overweight or obesity were more likely to use supplements. In conclusion, many CRC survivors alter their diet post-diagnosis and use dietary supplements, in part for different reasons. Insights into motivations behind these lifestyle habits and characteristics of CRC survivors adopting these habits can improve the tailoring of lifestyle counselling strategies.
Some populations/groups are defined as hard to survey (H2S) in the research literature because of difficulty sampling the population, accessing the population, contacting members of the population, persuading them to participate, and interviewing group members (see Tourangeau, Chapter 1 in this volume). Reviewing the literature on populations referred to as “hard to survey” indicates the types of studies undertaken with these populations, the survey error challenges, and the methodological solutions used by researchers who study such populations. The H2S literature, however, does have limitations and research gaps exist.
The problems that complicate obtaining high-quality data from H2S populations are diverse and often interrelated. This review uses a quality assurance and quality control framework to discuss the total survey error associated with H2S studies. The discussion is based on an extensive systematic review of the quantitative and qualitative literature related to H2S, as well as our own experiences surveying these populations. (For a discussion and definition of kinds of H2S populations and the characteristics that earn them the H2S label, see Chapter 1 in this volume.)
Cultural and linguistic minorities can be hard to survey either as the target population of interest or as a subpopulation of a general population survey. The challenges associated with studying these minorities are important to understand in order to assess and address the survey error that can be introduced when designing and implementing studies that include these groups. This chapter begins with a description of what constitutes cultural and linguistic minorities, based on a systematic review of the literature (see Chapter 5 in this volume, for a complete description of the process). We note that the literature in this area is largely limited to research among cultural and linguistic minorities in the context of Western and industrialized countries. Therefore, we supplement this literature by drawing upon our own experience and discussions with colleagues who conduct research among cultural and linguistic minorities in other parts of the world. This review is followed by a discussion of the potential challenges faced by researchers interested in surveying cultural and linguistic minorities and approaches taken to address these challenges in the areas of sampling, questionnaire development, adaptation and translation, pretesting, and data collection. We then discuss additional approaches to studying these hard-to-survey populations including qualitative, mixed-methods, and community-based research methods and how these can complement survey methods. The concluding section addresses needed improvements in the documentation and development of research methods to expand solutions and increase the quality of hard-to-survey cultural and linguistic minority research.
Defining cultural and linguistic minorities
This section sets out the key features of cultural and linguistic minorities. Three core concepts are defined and discussed. First, we define minority populations followed by a discussion of linguistic and cultural minorities. The distinct concept of hard-to-survey is also relevant and discussed in this context (also see Chapter 1 in this volume). On the one hand, it is a relatively straightforward task to define these concepts; however, as we discuss below, applying these definitions in a survey context is far more complicated. Formal definitions serve as a good starting point for this discussion, however.