317 research outputs found

    Solar warming of near-bottom water over a fringing reef

    Get PDF
    The Kilo Nalu Observatory is located on the foreslope of a fringing reef on the south shore of Oahu, Hawaii. A cabled node at 12-m depth has enabled continuous real-time temperature observations from a thermistor chain extending from 1 to 7 m above bottom. Data from a 27-month deployment in 2007–2009 reveal repeated instances of subsurface temperature inversions. The usual diurnal pattern shows increases in temperature throughout the water column after sunrise, peaking in the early afternoon. Bottom waters typically warm faster than those at mid-depth, driving an inversion in the thermal profile. The onset and evolution of the inversions are consistent with an analytical model of radiation absorption and the contribution to bottom temperature from solar warming of the seafloor. The maximum size, duration and seasonal distribution of the inversions indicate that salinity compensation is a major limiting factor. In the absence of salinity compensation, the implication is that bottom heating destabilizes the water column and convective transport results. In addition, recurring afternoon onshore bottom currents contribute to the termination of inversions. Although radiative heating may exacerbate coral heat stress, radiation-driven thermal convection and exposure to the open ocean modulate temperatures over the reef

    The importance of interocean exchange south of Africa in a numerical model

    Get PDF
    A fine resolution numerical model of the Southern Ocean (the Fine Resolution Antarctic Model (FRAM)) has been used to investigate the way in which heat is supplied to the South Atlantic. The heat budget in the model is compared with other estimates and is found to be broadly realistic. The temperature structure in the Atlantic, and therefore the meridional heat transport, depend heavily on the input of heat from the Indian Ocean via the Agulhas Retroflection region. FRAM is compared with three models which do not exhibit a significant input of heat from the Indian Ocean. These models also have a lower equatorward heat transport in the South Atlantic. Horizontal resolution affects the amount of Agulhas transfer with coarser resolution leading to lower heat transport in the Atlantic, a result which has implications for ocean models used in climate simulations

    Climate‐related variations in mixing dynamics in an Alaskan arctic lake

    Full text link
    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109805/1/lno2009546part22401.pd

    Parenting Styles Are Associated With Overall Child Dietary Quality Within Low-Income and Food-Insecure Households

    Get PDF
    Objective: To examine the association between parenting styles and overall child dietary quality within households that are low-income and food-insecure. Design: Child dietary intake was measured via a 24 h dietary recall. Dietary quality was assessed using the Healthy Eating Index-2005 (HEI-2005). Parenting styles were measured and scored using the Parenting Styles and Dimensions Questionnaire. Linear regressions were used to test main and interaction associations between HEI-2005 scores and parenting styles. Setting: Non-probability sample of low-income and food-insecure households in South Carolina, USA. Participants: Parent–child dyads (n 171). Parents were ≥18 years old and children were 9–15 years old. Results: We found a significant interaction between authoritative and authoritarian parenting style scores. For those with a mean authoritarian score, each unit increase in authoritative score was associated with a higher HEI-2005 score (b = 3·36, P \u3c 0.05). For those with an authoritarian score that was 1 SD above the mean authoritarian score, each unit increase in authoritative score was associated with a higher HEI-2005 score (b = 8.42, P \u3c 0.01). For those with an authoritarian score that was −1 SD below the mean authoritarian score, each unit increase in authoritative score was associated with a lower HEI-2005 score; however, this was not significant (b = −1·69, P \u3e 0·05). Permissive parenting style scores were negatively associated with child dietary quality (b = −2·79, P \u3c 0·05). Conclusions: Parenting styles should be considered an important variable that is associated with overall dietary quality in children living within low-income and food-insecure households

    Programmable antivirals targeting critical conserved viral RNA secondary structures from influenza A virus and SARS-CoV-2

    Get PDF
    Influenza A virus’s (IAV’s) frequent genetic changes challenge vaccine strategies and engender resistance to current drugs. We sought to identify conserved and essential RNA secondary structures within IAV’s genome that are predicted to have greater constraints on mutation in response to therapeutic targeting. We identified and genetically validated an RNA structure (packaging stem–loop 2 (PSL2)) that mediates in vitro packaging and in vivo disease and is conserved across all known IAV isolates. A PSL2-targeting locked nucleic acid (LNA), administered 3 d after, or 14 d before, a lethal IAV inoculum provided 100% survival in mice, led to the development of strong immunity to rechallenge with a tenfold lethal inoculum, evaded attempts to select for resistance and retained full potency against neuraminidase inhibitor-resistant virus. Use of an analogous approach to target SARS-CoV-2, prophylactic administration of LNAs specific for highly conserved RNA structures in the viral genome, protected hamsters from efficient transmission of the SARS-CoV-2 USA_WA1/2020 variant. These findings highlight the potential applicability of this approach to any virus of interest via a process we term ‘programmable antivirals’, with implications for antiviral prophylaxis and post-exposure therapy

    Theorising variation in engagement in professional and curriculum development: performativity, capital, systems and purpose

    Get PDF
    Increasingly, policymakers seek to improve the quality of teaching through curriculum innovations and continuing professional development (CPD) programmes. However, engagement by schools and teachers varies due to mediating influences of neoliberal policies. In this article, we contribute to understanding how these tendencies affect participation. Problematising the notion of context, we examine ways in which systemic influences interacted with participation in a government-funded mathematics professional and curriculum development programme and also with participants’ purposes. A 3-level clustered Randomised Controlled Trial (RCT) and an implementation and process evaluation were augmented by in-depth case studies, cross-case analysis and the application of theoretical constructs to interpret findings. Theories of capital, figured worlds and systemic coupling are utilised to theorise context. Different levels of engagement are partly explainable by: the interaction of schools' relative systemic advantage and disadvantage; their orientation and coupling to performativity regimes; and the alignment or dissonance between continuing professional development or change programmes and the pedagogical and CPD cultures and purposes of the ‘actors’ (schools, departments and teachers). Performativity concerns restricted what were considered legitimate outcomes in some case study schools. This depended on teachers and schools' positioning in terms of relative degrees of systemic privilege or disadvantage - understood as economic, cultural, social and symbolic capital - and also in terms of figured worlds and system coupling. The case studies provide insights into how collaborative professional learning can be fostered more productively. Methodologically, we demonstrate the power of combining methodologies and applying explanatory social theory to augment quasi-experimental paradigms
    corecore