223 research outputs found

    The Effects of Carbon Dioxide Removal on the Carbon Cycle

    Get PDF
    Increasing atmospheric CO2 is having detrimental effects on the Earth system. Societies have recognized that anthropogenic CO2 release must be rapidly reduced to avoid potentially catastrophic impacts. Achieving this via emissions reductions alone will be very difficult. Carbon dioxide removal (CDR) has been suggested to complement and compensate for insufficient emissions reductions, through increasing natural carbon sinks, engineering new carbon sinks, or combining natural uptake with engineered storage. Here, we review the carbon cycle responses to different CDR approaches and highlight the often-overlooked interaction and feedbacks between carbon reservoirs that ultimately determines CDR efficacy. We also identify future research that will be needed if CDR is to play a role in climate change mitigation, these include coordinated studies to better understand (i) the underlying mechanisms of each method, (ii) how they could be explicitly simulated, (iii) how reversible changes in the climate and carbon cycle are, and (iv) how to evaluate and monitor CDR

    Variation in pre- and post-copulatory sexual selection on male genital size in two species of lygaeid bug

    Get PDF
    This study was funded by the Natural Environmental Research Council (DTG studentship 1109354 to LRD).Sexual selection has been shown to be the driving force behind the evolution of the sometimes extreme and elaborate genitalia of many species. Sexual selection may arise before and/or after mating, or vary according to other factors such as the social environment. However, bouts of selection are typically considered in isolation. We measured the strength and pattern of selection acting on the length of the male intromittent organ (or processus) in two closely related species of lygaeid seed bug: Lygaeus equestris and Lygaeus simulans. In both species, we measured both pre- and post-copulatory selection. For L. equestris, we also varied the experimental choice design used in mating trials. We found contrasting pre- and post-copulatory selection on processus length in L. equestris. Furthermore, significant pre-copulatory selection was only seen in mating trials in which two males were present. This selection likely arises indirectly due to selection on a correlated trait, as the processus does not interact with the female prior to copulation. In contrast, we were unable to detect significant pre- or post-copulatory selection on processus length in L. simulans. However, a formal meta-analysis of previous estimates of post-copulatory selection on processus length in L. simulans suggests that there is significant stabilising selection across studies, but the strength of selection varies between experiments. Our results emphasise that the strength and direction of sexual selection on genital traits may be multifaceted and can vary across studies, social contexts and different stages of reproduction.Publisher PDFPeer reviewe

    Shape - but Not Size - Codivergence between Male and Female Copulatory Structures in Onthophagus Beetles

    Get PDF
    Genitalia are among the fastest evolving morphological traits in arthropods. Among the many hypotheses aimed at explaining this observation, some explicitly or implicitly predict concomitant male and female changes of genital traits that interact during copulation (i.e., lock and key, sexual conflict, cryptic female choice and pleiotropy). Testing these hypotheses requires insights into whether male and female copulatory structures that physically interact during mating also affect each other's evolution and patterns of diversification. Here we compare and contrast size and shape evolution of male and female structures that are known to interact tightly during copulation using two model systems: (a) the sister species O. taurus (1 native, 3 recently established populations) and O. illyricus, and (b) the species-complex O. fracticornis-similis-opacicollis. Partial Least Squares analyses indicated very little to no correlation between size and shape of copulatory structures, both in males and females. Accordingly, comparing shape and size diversification patterns of genitalia within each sex showed that the two components diversify readily - though largely independently of each other - within and between species. Similarly, comparing patterns of divergence across sexes showed that relative sizes of male and female copulatory organs diversify largely independent of each other. However, performing this analysis for genital shape revealed a signature of parallel divergence. Our results therefore suggest that male and female copulatory structures that are linked mechanically during copulation may diverge in concert with respect to their shapes. Furthermore, our results suggest that genital divergence in general, and co-divergence of male and female genital shape in particular, can evolve over an extraordinarily short time frame. Results are discussed in the framework of the hypotheses that assume or predict concomitant evolutionary changes in male and female copulatory organs

    The ACCESS study a Zelen randomised controlled trial of a treatment package including problem solving therapy compared to treatment as usual in people who present to hospital after self-harm: study protocol for a randomised controlled trial

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>People who present to hospital after intentionally harming themselves pose a common and important problem. Previous reviews of interventions have been inconclusive as existing trials have been under powered and done on unrepresentative populations. These reviews have however indicated that problem solving therapy and regular written communications after the self-harm attempt may be an effective treatment. This protocol describes a large pragmatic trial of a package of measures which include problem solving therapy, regular written communication, patient support, cultural assessment, improved access to primary care and a risk management strategy in people who present to hospital after self-harm using a novel design.</p> <p>Methods</p> <p>We propose to use a double consent Zelen design where participants are randomised prior to giving consent to enrol a large representative cohort of patients. The main outcome will be hospital attendance following repetition of self-harm, in the 12 months after recruitment with secondary outcomes of self reported self-harm, hopelessness, anxiety, depression, quality of life, social function and hospital use at three months and one year.</p> <p>Discussion</p> <p>A strength of the study is that it is a pragmatic trial which aims to recruit large numbers and does not exclude people if English is not their first language. A potential limitation is the analysis of the results which is complex and may underestimate any effect if a large number of people refuse their consent in the group randomised to problem solving therapy as they will effectively cross over to the treatment as usual group. However the primary analysis is a true intention to treat analysis of everyone randomised which includes both those who consent and do not consent to participate in the study. This provides information about how the intervention will work in practice in a representative population which is a major advance in this study compared to what has been done before.</p> <p>Trial registration</p> <p>Australia and New Zealand Clinical Trials Register (ANZCTR): <a href="http://www.anzctr.org.au/ACTRN12609000641291.aspx">ACTRN12609000641291</a></p

    Organizational practices across cultures: An exploration in six cultural contexts

    Get PDF
    This study examined organizational practices in a sample of 1239 employees from various organizations in Argentina, Brazil, Malaysia, New Zealand, Turkey, and the United States. Twenty-four items measuring employee-orientation, formalization, and innovation practices showed a clear factorial structure across all samples, along with good reliabilities. Significant organizational position differences were found for employee-orientation and innovation practices. Sector differences were found for formalization and innovation practices. Cultural differences were found for employee-orientation and innovation practices, which can be explained using macroeconomic indicators,tightness–looseness, and individualism. Our study demonstrates the importance of individual, organizational, economic, and cultural level for understanding perceptions of organizational practices across a wider range of societies

    Transition from children's to adult services for adolescents/young adults with life-limiting conditions : developing realist programme theory through an international comparison

    Get PDF
    Abstract Background Managing transition of adolescents/young adults with life-limiting conditions from children’s to adult services has become a global health and social care issue. Suboptimal transitions from children’s to adult services can lead to measurable adverse outcomes. Interventions are emerging but there is little theory to guide service developments aimed at improving transition. The Transition to Adult Services for Young Adults with Life-limiting conditions (TAYSL study) included development of the TASYL Transition Theory, which describes eight interventions which can help prepare services and adolescents/young adults with life-limiting conditions for a successful transition. We aimed to assess the usefulness of the TASYL Transition Theory in a Canadian context to identify interventions, mechanisms and contextual factors associated with a successful transition from children’s to adult services for adolescents/young adults; and to discover new theoretical elements that might modify the TASYL Theory. Methods A cross-sectional survey focused on organisational approaches to transition was distributed to three organisations providing services to adolescents with life-limiting conditions in Toronto, Canada. This data was mapped to the TASYL Transition Theory to identify corresponding and new theoretical elements. Results Invitations were sent to 411 potentially eligible health care professionals with 56 responses from across the three participating sites. The results validated three of the eight interventions: early start to the transition process; developing adolescent/young adult autonomy; and the role of parents/carers; with partial support for the remaining five. One new intervention was identified: effective communication between healthcare professionals and the adolescent/young adult and their parents/carers. There was also support for contextual factors including those related to staff knowledge and attitudes, and a lack of time to provide transition services centred on the adolescent/young adult. Some mechanisms were supported, including the adolescent/young adult gaining confidence in relationships with service providers and in decision-making. Conclusions The Transition Theory travelled well between Ireland and Toronto, indicating its potential to guide both service development and research in different contexts. Future research could include studies with adult service providers; qualitative work to further explicate mechanisms and contextual factors; and use the theory prospectively to develop and test new or modified interventions to improve transition

    Qualitative evaluation of mental health services for clients with limited English proficiency

    Full text link
    BACKGROUND: To meet federal requirements under Title VI of the Civil Rights Act, the state of California instituted policies requiring that comprehensive mental health services in native languages be made available to limited English proficiency (LEP) populations when concentrations exceed “threshold” levels. METHODS: This paper builds on promising results from quantitative evaluations by reporting on qualitative interviews with Latino and Vietnamese LEP clients in mental health services (N = 20) to examine the awareness, impact, and implications of these threshold language policies. RESULTS: Results suggest that, while individuals are often not aware of the policies themselves, the language-related services they receive that are prompted by the policies are critical to treatment initiation and retention. Results also convey the complexities of using interpreters for sensitive psychological topics, and suggest that, for LEP individuals seeking mental health treatment, providers who speak their native languages are generally preferred. CONCLUSIONS: Access to language-appropriate services seems to be an important part of why LEP populations seek mental health treatment. However, there are multiple variables that factor into the usage and usefulness of such services

    Altering micro-environments to change population health behaviour: towards an evidence base for choice architecture interventions.

    Get PDF
    BACKGROUND: The idea that behaviour can be influenced at population level by altering the environments within which people make choices (choice architecture) has gained traction in policy circles. However, empirical evidence to support this idea is limited, especially its application to changing health behaviour. We propose an evidence-based definition and typology of choice architecture interventions that have been implemented within small-scale micro-environments and evaluated for their effects on four key sets of health behaviours: diet, physical activity, alcohol and tobacco use. DISCUSSION: We argue that the limitations of the evidence base are due not simply to an absence of evidence, but also to a prior lack of definitional and conceptual clarity concerning applications of choice architecture to public health intervention. This has hampered the potential for systematic assessment of existing evidence. By seeking to address this issue, we demonstrate how our definition and typology have enabled systematic identification and preliminary mapping of a large body of available evidence for the effects of choice architecture interventions. We discuss key implications for further primary research, evidence synthesis and conceptual development to support the design and evaluation of such interventions. SUMMARY: This conceptual groundwork provides a foundation for future research to investigate the effectiveness of choice architecture interventions within micro-environments for changing health behaviour. The approach we used may also serve as a template for mapping other under-explored fields of enquiry

    Is social stress in the first half of life detrimental to later physical and mental health in both men and women?

    Get PDF
    This study examined gender differences in the associations between affection- and status-related stressors encountered in the first half of life and physical and mental health problems later on. Based on the theory of Social Production Functions (SPF) two hypotheses have been formulated, which were tested in a representative sample of 446 men and 514 women (aged 40–79). Main outcome measures were number of chronic somatic diseases and level of psychological distress. As expected, regression analyses showed no gender differences in the associations between affection-related stressors and physical and mental health problems later on. In contrast, but as also expected, status-related stressors encountered in the first half of life were associated with later physical and mental health for men only. It is concluded that the gender differences in the associations between earlier social stressors and later health problems may be more complex than the common assumption that men are only affected by status stress and women only by affection stress. This study contributes to the knowledge on gender differences concerning the link between social stress and health, and it indicates that social experiences encountered earlier in life are of importance for being healthy and happy in later life
    corecore