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Abstract Subanesthetic ketamine is increasingly used for the treatment of varied psychiatric conditions, both on- and off-label. While it is commonly classified as an N-methyl D-aspartate receptor (NMDAR) antagonist, our picture of ketamine’s mechanistic underpinnings is incomplete. Recent clinical evidence has indicated, controversially, that a component of the efficacy of subanesthetic ketamine may be opioid dependent. Using pharmacological functional ultrasound imaging in rats, we found that blocking opioid receptors suppressed neurophysiologic changes evoked by ketamine, but not by a more selective NMDAR antagonist, in limbic regions implicated in the pathophysiology of depression and in reward processing. Importantly, this opioid-dependent response was strongly sex-dependent, as it was not evident in female subjects and was fully reversed by surgical removal of the male gonads. We observed similar sex-dependent effects of opioid blockade affecting ketamine-evoked postsynaptic density and behavioral sensitization, as well as in opioid blockade-induced changes in opioid receptor density. Together, these results underscore the potential for ketamine to induce its affective responses via opioid signaling, and indicate that this opioid dependence may be strongly influenced by subject sex. These factors should be more directly assessed in future clinical trials.

We generalize a native Nb 2 O 5 dissolution model [G. Ciovati, Appl. Phys. Lett. 89, 022507 (2006)] to sequential overlayer dissolutions, multilayer dissolution, and realistic temperature profiles, which may be applicable to other materials. The model is applied to secondary ion mass spectrometry depth profile measurements for varying temperature profiles and two-step oxide dissolution in Nb and found to agree well. In the context of the Meissner screening response due to impurity profiles on the length scale of the London penetration depth, the shallow diffusion of O impurities results in a substantial decrease in the peak supercurrent density near the surface. In this framework, oxide dissolution and oxygen diffusion can account for a rise in peak supportable magnetic field in SRF cavities with baking time and a suppression after the optimal baking time is reached, in good agreement with peak-field baking temperatures and times as well as recent quench field measurements. [ABSTRACT FROM AUTHOR]

This article synthesises principles towards achieving responsible waste management in South African protected areas. These principles are distilled from and based on existing legislation, guidelines and best practices applicable to environmental management, waste management and protected areas management. The principles are framed around the South African environmental management principles, and specifically contextualised for waste management in protected areas, based on legislation, guidelines and best practices from the literature. Six key principles are synthesised, which aim to achieve responsible waste management in protected areas through: (1) protection of ecosystems and biodiversity; (2) prevention and remediation of pollution; (3) implementation of the waste management hierarchy; (4) provision of effective waste services and infrastructure; (5) promotion of participation and building of partnerships; and (6) contribution to wellbeing, livelihoods and capacity. These principles provide a first step towards the development of detailed guidance on dealing with waste management in South African protected areas and may have relevance in other countries. Conservation implications: The suggested principles for responsible waste management in protected areas aim to provide strategic direction, coordinate and standardise waste management in protected areas. The ultimate aim of the principles is to reduce the adverse impacts of waste in protected areas and to align waste management practices with South African laws and international best practice.

Abstract Fieldwork, including work done at sea, is a key component of many geoscientists' careers. Recent studies have highlighted the pervasive harassment faced by women and LGBTQ+ people during fieldwork. However, transgender and gender diverse (TGD) scientists face obstacles which have not yet been thoroughly examined. We fill this gap by sharing our experiences as TGD people. We have experienced sexual harassment, misconduct, privacy issues, and legal and medical struggles as we conduct seagoing work. In this work, we provide recommendations for individuals, cruise leaders, and institutions for making seagoing work safer for our communities.

The aim of this paper is to evaluate the environmental performance of luxury safari lodges along a performance pathway from legal compliance to best practice. The research results provide a conceptual framework and performance baseline against which lodges can then develop strategies to improve environmental performance. We achieve this aim by adapting the sustainability journey conceptual framework of Willard (2005), that describes five phases of progression along a business performance pathway, from legal compliance to best practice. Performance areas and indicators are developed against the adapted framework covering water, waste, energy and infrastructure development, applied to 12 luxury safari lodges within the South African context. The results show that poor performance was recorded for water management, whilst energy management fared slightly better. Overall performance in relation to waste and infrastructure development fared the best.

The mismanagement of waste in protected areas may lead to significant and irreversible environmental, economic and social impacts, such as land degradation, resource depletion, surface and groundwater pollution, loss of biodiversity and impacts on the aesthetic value of these areas. This paper aims to identify the challenges and opportunities for sustainable solid waste management in privately protected areas, given the limited research conducted on this topic. A case study approach was followed, which focused on the Sabi Sand Wildtuin, a private nature reserve (PNR) in South Africa. Interviews were conducted with 30 participants, which included representatives from the management authority, commercial lodges, non-commercial properties and a waste service provider. Several challenges have been identified by interviewees. Behaviour was the most frequently mentioned challenge, where interviewees raised concerns about negative attitudes, unwillingness to implement waste management measures and a possible lack of support. Other frequently mentioned challenges included foreseen difficulties due to the size and location of the reserve and concerns around funding of waste management measures, especially given the financial implications of coronavirus disease 2019 (COVID-19) travel and tourism restrictions. The most frequently identified opportunities included creating jobs and improving livelihoods, providing assurance and transparency of what happens to waste ‘beyond the gate’ and improving awareness, knowledge and skills related to waste management. To optimise the opportunities towards sustainable solid waste management, PNRs should focus on aligning their strategic direction to achieve legal compliance and support community initiatives to establish waste-related infrastructure and services that cannot be implemented within the reserve. Conservation implications: The pursuit of waste-related opportunities within privately protected areas could enhance the implementation of sustainable solid waste management in PNRs, whilst also contributing to pollution prevention, community upliftment and other secondary benefits, which could ultimately result in increased conservation efforts.

This research evaluates Environmental Impact Assessment (EIA) report quality for a selected sample of development projects in South African national parks. It applies an adapted version of an international EIA report quality review package to 24 developments within 10 national parks, across three EIA regimes. The results suggest good EIA report quality across all four quality review areas, with improvement over time, but also highlight particular weaknesses in terms of dealing with waste and, to a lesser extent, with significance and mitigation. To build on this research, the development of a sector-specific EIA report quality review package is recommended, with more emphasis on the strategic context, waste and water-related aspects. The conclusion is that EIA is well positioned to remain an important decision support instrument for developments within national parks. Conservation implications: The results show that EIA reports for developments in South African national parks are generally of sufficient quality for decision-making that benefits conservation. However, weaker performance regarding waste, significance determination, water-related impacts and a lack of consideration of strategic context requires a conservation-specific EIA report quality review package to improve report quality in the areas of weakness and thereby increase the value of EIA as an instrument for environmental governance and sustainable development in conservation areas.

Purpose: 6-O-(2-[18F]Fluoroethyl)-6-O-desmethyl-diprenorphine ([18F]FE-DPN) is regarded as a non-selective opioid receptor radiotracer. Procedure: Here, we report the first characterization of [18F]FE-DPN synthesized from the novel precursor, 6-O-(2-tosyloxyethoxy)-6-O-desmethyl-3-O-trityl-diprenorphine (TE-TDDPN), using a one-pot, two-step nucleophilic radiosynthesis to image opioid receptors in rats and mice using positron emission tomography. Results: We also show that [18F]FE-DPN and [3H]DPN exhibit negligible brain uptake in mu opioid receptor (MOR) knockout mice. Conclusions: Taken together with prior findings, our results suggest that [18F]FE-DPN and [3H]DPN preferentially bind to MOR in rodents in vivo. [ABSTRACT FROM AUTHOR]