692 research outputs found

    Hydrodynamic impacts of tectonics in prehistoric Ohiwa Harbour, North Island, New Zealand

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    Ohiwa Harbour is an estuarine lagoon located in the eastern Bay of Plenty, North Island, New Zealand. Ohiwa Harbour is bounded by two sand spits, Ohope and Ohiwa Spits. This study assessed the likelihood of a resistant barrier underlying Ohiwa Spit, which would control the inlet and spit locations. The observed depths of layers unable to be penetrated by a vibrocorer on Ohiwa Spit supported this idea, along with the discovery of a rock outcrop on the eastern harbour entrance using sidescan SONAR. Vibrocoring on Ohiwa Spit added to the knowledge of the prehistoric evolution of Ohiwa Harbour, and an attempt to infer various subsidence events on Ohiwa Spit were made. Fining upwards coarse sand sequences with dominant shell material were found in the cores. These sequences could be related to a change in harbour hydrodynamics, or recent subsidence events in Ohiwa Harbour, such as the 0.6m subsidence of the Waimana Fault 636 to 575cal yrs BP. A sharp change in the core profile was observed at 1.4m in core C and 1.7m in core C2, marked by increased grain size and an abundance of shell material, mostly Austrovenus stutchburyi. This could be related to a change in wave energy in the harbour or an erosional contact associated with subsidence of Ohiwa Spit. Comparison of radiocarbon dated shells in this study with Murdoch (2005) on Ohope Spit suggests that more subsidence has occurred at Ohiwa Spit than Ohope Spit; this may be associated with a fault through the harbour entrance. Subsidence associated with earthquakes, and erosion associated with at least four tsunami events in the last 6000 years has increased the depth and extent of Ohiwa Harbour, increasing its volume. This study used numerical modeling to determine the hydrodynamic impacts of past catastrophic events (earthquake related subsidence and volcanic eruptions) on Ohiwa Harbour. Ten scenarios along with present conditions were modelled. • In scenarios where sea level was modified only (scenarios 1-5 and 8), tidal range and surface elevation increased within the harbour, but not at the harbour entrance. The entrance hydrodynamics were also influenced by its width; as Ohope Spit accreted, the surface elevation and flow velocities increased within the tidal inlet • Flow speeds increased at the harbour entrance by up to 50% following subsidence in scenarios 9 and 10 • A drop in sea level during subsidence (scenario 6) resulted in a smaller tidal prism and hence reduced flow velocities at the inlet, despite the subsidence • Scenario 7 involved subsidence and the breaching of Ohope Spit, which would divert flow away from the entrance and result in reduced flow velocities at the entranc

    Cooking for communities, children and cows: lessons learned from institutional cookstoves in Nepal

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    Despite a long history of Improved Cookstove (ICS) interventions by Non-Governmental Organizations, International Development partners and the Government of Nepal, the majority of rural Nepalese people cook on a traditional open fire for their large-scale cooking needs due to a significant lack of approved institutional-scale cooking solutions. Whilst 65.8% of rural Nepalese households cook with biomass as their primary fuel source to satisfy their personal energy needs, there is no information collected on institutional cooking use by the Government of Nepal. In this paper our main objective was to design, implement and evaluate a novel Institutional Improved Cookstove (IICS) to satisfy this gap and following its manufacturing and testing in a Government of Nepal approved test center, to identify the complex contextual factors that often override the technical capabilities of IICS. Our three-phase method combined qualitative and quantitative research approaches, as well as north-south collaborations involving a transdisciplinary research team to create an integrated systems approach taking into account the voices of all key energy stakeholders. Phase 1 included UK based co-design and testing at the University of Nottingham in 2017 to develop a novel IICS that could be used in rural Nepal. Phase 2 involved adapting the design to accommodate contextual factors highlighted by Nepalese partners and to meet testing requirements at a Government of Nepal approved testing center in late 2017. Phase 3 was conducted between December 2017 and April 2020 and focused on piloting the novel IICS in a range of locations, altitudes, socio-economic and cultural settings, monitoring sustained use and obtaining user feedback. We present our results through three case studies that highlight the highly contextualized nature of IICS adoption and sustained use, the importance of stacking, usability and cost savings, and a number of pathways to scale in an institutional setting

    High rates of missed HIV testing among oral PrEP users in the United States from 2018-2021: A national assessment on compliance with HIV testing recommendations of the CDC PrEP guidelines

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    BACKGROUND: The US Centers for Disease Control and Prevention recommends HIV testing every 3 months in oral PrEP users. We performed a national assessment of HIV testing compliance among oral PrEP users. METHODS: We analyzed 408 910 PrEP prescriptions issued to 39 809 PrEP users using a national insurance claims database that contained commercial and Medicaid claims. We identified PrEP use based on pharmacy claims and outpatient diagnostic coding. We evaluated the percentage of PrEP prescription refills without HIV testing (identified by CPT codes) within the prior 3, 6, and 12 months using time to event methods. We performed subgroup and multivariate analyses by age, gender, race, insurance type, and geography. RESULTS: Of 39 809 persons, 36 197 were commercially insured, 3612 were Medicaid-insured, and 96% identified as male; the median age (interquartile range) was 34 (29-44) years, and the Medicaid-insured PrEP users were 24% Black/African American, 44% White, and 9% Hispanic/Latinx. Within the prior 3, 6, and 12 months, respectively, the percentage of PrEP prescription fills in individuals without HIV Ag/Ab testing was 34.3% (95% CI, 34.2%-34.5%), 23.8% (95% CI, 23.7%-23.9%), and 16.6% (95% CI, 16.4%-16.7%), and the percentage without any type of HIV test was 25.8% (95% CI, 25.6%-25.9%), 14.6% (95% CI, 14.5%-14.7%), and 7.8% (95% CI, 7.7%-7.9%). CONCLUSIONS: Approximately 1 in 3 oral PrEP prescriptions were filled in persons who had not received an HIV Ag/Ab test within the prior 3 months, with evidence of health disparities. These findings inform clinical PrEP monitoring efforts and compliance with national HIV testing guidance to monitor PrEP users

    Understanding the current market enablers for Nepal’s biomass cookstove industry

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    This paper applies the market map tool to the Nepalese biomass cookstove market highlighting existing weaknesses in government policy, cookstove market chains and providing a framework for cookstove interventions that better address the social, economic and cultural needs of users. Findings indicate government policy actively promotes cooking technologies however, this may not result in sustained use. Tracking mechanisms focus on numbers of stoves disseminated rather than numbers used. Attention is given to links between the underdeveloped nature of the institutional cookstove market and restrictive government policy. The methodological approach involved semi-structured interviews, field observations and analysis of government policy documents. Abstract This paper applies the Market Map tool to the Nepalese biomass Improved Cookstove (ICS) sector highlighting existing weaknesses in government policy and biomass cookstove market chains to provide recommendations to better address the social, economic and cultural needs of users. This addresses the problem of low adoption rates of biomass ICS in Nepal. Our research objectives set out to explore the effectiveness of market maps designed for East Africa's ICS sector (Stevens et al., 2019) in Nepal, co-develop a revised market map for Nepal's biomass ICS sector, conduct a parallel process for institutional-scale biomass ICS and draw on the co-produced market map to inform policy and regulatory frameworks relating to biomass-fuelled ICS. The methodological approach involved reviewing cookstove-related policy documents and regulatory frameworks, undertaking 31 semi-structured interviews, analysing findings from an Institutional Top-Loading Down-Draft (TLUD) Natural Draft Gasifier Pilot study and co-developing the final market map in collaboration with key ICS stakeholders. The results indicate that although government policy actively promotes biomass ICS, this often results in cookstove 'stacking' rather than the sustained and exclusive use of clean cooking solutions necessary to promote health benefits. Attention is also focused on the underdeveloped nature of the institutional cookstove market. Our conclusions highlight the usefulness of market maps with a monitoring and evaluation element for identifying barriers to clean cooking uptake and facilitating product improvement by integrating end-user feedback

    Pharmaceutical integrated stress response enhancement protects oligodendrocytes and provides a potential multiple sclerosis therapeutic.

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    Oligodendrocyte death contributes to the pathogenesis of the inflammatory demyelinating disease multiple sclerosis (MS). Nevertheless, current MS therapies are mainly immunomodulatory and have demonstrated limited ability to inhibit MS progression. Protection of oligodendrocytes is therefore a desirable strategy for alleviating disease. Here we demonstrate that enhancement of the integrated stress response using the FDA-approved drug guanabenz increases oligodendrocyte survival in culture and prevents hypomyelination in cerebellar explants in the presence of interferon-γ, a pro-inflammatory cytokine implicated in MS pathogenesis. In vivo, guanabenz treatment protects against oligodendrocyte loss caused by CNS-specific expression of interferon-γ. In a mouse model of MS, experimental autoimmune encephalomyelitis, guanabenz alleviates clinical symptoms, which correlates with increased oligodendrocyte survival and diminished CNS CD4+ T cell accumulation. Moreover, guanabenz ameliorates relapse in relapsing-remitting experimental autoimmune encephalomyelitis. Our results provide support for a MS therapy that enhances the integrated stress response to protect oligodendrocytes against the inflammatory CNS environment

    Lafite in China

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    Increased economic power has positioned China within the global elite, yet China’s legitimacy remains low with regard to hierarchies of taste. Drawing from Bourdieu and Elias, this article offers an account of the global dynamics of status contests, and the role played by cultural capital and notions of civility and vulgarity. Specifically, we examine how U.S., UK, and Chinese media represent Chinese consumption of fine wine, and particularly that of Château Lafite, in the 2000 to 2013 period. Our analysis reveals four major ways in which Chinese fine wine consumption is framed—as vulgar, popular, functional, and discerning—and highlights tensions between Western and Chinese terms of cultural legitimacy. The research uncovers nuanced dimensions to the “East/West” divide in terms of the grades of cultural capital, competing logics of valuation, and modes of civility at play. Macromarketing implications of fine wine consumption in a fragmented and complex market are discussed

    Uniformity in the Wiener-Wintner theorem for nilsequences

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    We prove a uniform extension of the Wiener-Wintner theorem for nilsequences due to Host and Kra and a nilsequence extension of the topological Wiener-Wintner theorem due to Assani. Our argument is based on (vertical) Fourier analysis and a Sobolev embedding theorem.Comment: v3: 18 p., proof that the cube construction produces compact homogeneous spaces added, measurability issues in the proof of Theorem 1.5 addressed. We thank the anonymous referees for pointing out these gaps in v

    Unique V3 Loop Sequence Derived from the R2 Strain of HIV-Type 1 Elicits Broad Neutralizing Antibodies

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    DNA vaccines expressing the envelope (Env) of the human immunodeficiency virus type 1 (HIV-1) have been relatively ineffective at generating high-titer, long-lasting, neutralizing antibodies. In this study, DNA vaccines were constructed to express the gp120 subunit of Env from the isolate HIV-1R2 using both wild-type and codon- ptimized gene sequences. Three copies of the murine C3d were added to the carboxyl terminus to enhance the immunogenicity of the expressed fusion protein. Mice (BALB/c) vaccinated with DNA plasmid expressing the gp120R2 using codon-optimized Env sequences elicited high-titer anti-Env antibodies regardless of conjugation to C3d. In contrast, only mice vaccinated with DNA using wild-type gp120R2 sequences fused to mC3d3, had detectable anti- Env antibodies. Interestingly, mice vaccinated with DNA expressing gp120R2 from codon-optimized sequences elicited antibodies that neutralized both homologous and heterologous HIV-1 isolates. To determine if the unique sequence found in the crown of the V3 loop of the EnvR2 was responsible for the elicitation of the cross-clade neutralizing antibodies, the codons encoding for the Pro-Met (amino acids 313–314) were introduced into the sequences encoding the gp120ADA (R5) or gp12089.6 (R5X4). Mice vaccinated with gp120ADA–mC3d3–DNA with the Pro–Met mutation had antibodies that neutralized HIV-1 infection, but not the gp12089.6–mC3d3–DNA. Therefore, the use of the unique sequences in the EnvR2 introduced into an R5 tropic envelope, in conjunction with C3d fusion, was effective at broadening the number of viruses that could be neutralized. However, the introduction of this same sequence into an R5X4-tropic envelope was ineffective in eliciting improved cross-clade neutralizing antibodies. Originally published AIDS Research and Human Retroviruses, Vol. 20, No. 11, Nov 200

    Quantum Interference and Contact Effects in the Thermoelectric Performance of Anthracene-Based Molecules

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    We report on the single-molecule electronic and thermoelectric properties of strategically chosen anthracene-based molecules with anchor groups capable of binding to noble metal substrates, such as gold and platinum. Specifically, we study the effect of different anchor groups, as well as quantum interference, on the electric conductance and the thermopower of gold/single-molecule/gold junctions and generally find good agreement between theory and experiments. All molecular junctions display transport characteristics consistent with coherent transport and a Fermi alignment approximately in the middle of the highest occupied molecular orbital/lowest unoccupied molecular orbital gap. Single-molecule results are in agreement with previously reported thin-film data, further supporting the notion that molecular design considerations may be translated from the single- to many-molecule devices. For combinations of anchor groups where one binds significantly more strongly to the electrodes than the other, the stronger anchor group appears to dominate the thermoelectric behavior of the molecular junction. For other combinations, the choice of electrode material can determine the sign and magnitude of the thermopower. This finding has important implications for the design of thermoelectric generator devices, where both n- and p-type conductors are required for thermoelectric current generation
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