Structures of smooth muscle myosin and heavy meromyosin in the folded, shutdown state

Remodelling of the contractile apparatus within smooth muscle cells is an essential process that allows effective contractile activity over a wide range of cell lengths. The thick filaments may be redistributed via depolymerisation into inactive myosin monomers that have been detected in vitro, in which the long tail has a folded conformation. The structure of this folded molecule has been controversial. Using negative stain electron microscopy of individual folded molecules from turkey gizzard we show they are more compact than previously described, with heads and the three segments of the folded tail closely packed. Smooth muscle heavy meromyosin (HMM), which lacks two-thirds of the tail, closely resembles the equivalent parts of whole myosin. Image processing reveals a characteristic head region morphology for both HMM and myosin whose features are identifiable by comparison with less compact molecules. The two heads associate asymmetrically: the tip of one motor domain touches the base of the other, resembling the blocked and free heads of this HMM when it forms 2-D crystals on lipid. The tail of HMM lies between the heads, contacting the blocked motor domain, unlike in the 2-D crystal. The tail of the intact myosin is bent sharply and consistently at two positions close to residues 1175 and 1535. The first bend position correlates with a skip in the coiled coil sequence, the second does not. The first segment runs between the heads from the head-tail junction. Unexpectedly, the other segments associate only with the blocked head rather than both heads, such that the second bend lies at a specific position near the C-lobe of the blocked head regulatory light chain. Quantitative analysis of tail flexibility shows that the single coiled coil of HMM has an apparent Young’s modulus of about 0.5 GPa. The folded tail of the intact molecule is less flexible indicating interactions between the segments. The folded tail does not modify the compact head arrangement but stabilises it, indicating a structural mechanism for the very low ATPase activity of the folded molecule

An economic assessment of the ecosystem service benefits derived from the SSSI biodiversity conservation policy in England and Wales

AbstractDespite significant conservation efforts, global biodiversity continues to decline. A key contributing factor has been a failure to fully recognise the range of ecosystem service benefits provided by biodiversity. In this paper, we use a case study relating to Sites of Special Scientific Interest (SSSI) in England and Wales to demonstrate the potential ecosystem service benefits that can be derived from biodiversity conservation policies. Our approach involved three stages: (1) a choice experiment to assess the economic value of ecosystem services delivered by SSSI sites; (2) a ‘weighting matrix’ to (a) assign ecosystem services to the different SSSI habitats and (b) identify the contribution that conservation management on SSSIs has on the delivery of these services; (3) estimation of the aggregated economic value of ecosystem services directly attributable to conservation management on SSSI sites.The public are willing to pay £956m annually to secure the levels of services and benefits currently delivered by SSSI conservation activities, and a further £769 million to secure the benefits that would be delivered if SSSIs were all in favourable condition. These benefit estimates significantly exceed the annual £111 million costs of managing SSSIs, demonstrating that investing in biodiversity conservation can be cost effective

Assessing Child-safe Culture and Practices in Organisational Settings: a Validation and Refinement of Kaufman\u27s Organisational Safety Climate Survey

Using an Australian sample of employees (n = 1068) we assessed the psychometric properties of Kaufman’s Organisational Safety Climate Survey and its practical utility for measuring child-safe culture within organisations. The 60-item survey was found to have adequate psychometric properties. Initial factor analyses indicated a unidimensional factor structure, despite the survey being originally conceptualised into four subscales. Cronbach’s α coefficients were .95 for the full survey, with subscales ranging from .65–.94. However, qualitative feedback from respondents indicated that the survey was somewhat laborious and repetitive, with some item ambiguity noted. Refinements to the survey resulted in a 24-item short-form survey. The psychometric properties of the short-form survey were re-assessed. Factor analyses indicated a three-factor solution. Despite a significant reduction in items, internal consistency of the scale was not compromised; reliability of subscales also improved. Validation of this short-form survey as an alternative, time-efficient measure to maximise employee participation and contribution, is recommended

The Netherlands

The mitigation hierarchy has been part of Dutch spatial planning and environmental laws since 1961 in regard to forests, with extensions to other nature conservation acts since the 1990s. Over the years these laws have changed, along with their interpretation and application. Consequently, the roles and responsibilities of the central and regional governments have also shifted, with responsibilities regarding the enforcement of the mitigation hierarchy being transferred from the national government to the twelve provinces. Since 2017, three nature conservation laws have been merged into a single Nature Conservation Act, with the aim of clarifying and simplifying regulations. In the years to come, the new Nature Conservation Act will be incorporated into an overarching Environment and Planning Act, together with dozens of other pieces of legislation related to spatial planning and the environment. In summary, while Dutch law takes account of no net loss and offset mechanisms, the plurality of designations and regulations applying to sites has proven confusing to both practitioners and regulators. This chapter outlines the main policy mechanisms related to the mitigation hierarchy in the Netherlands, the application thereof, as well as successes and failures as outlined in recent studies. Our particular focus is on biodiversity offsets, which have received much attention in recent years. We discuss the scale of application, the transparency and availability of documentation regarding offset projects, along with the various offsetting mechanisms currently in place (restoration offsets, in-lieu fees). We also briefly touch upon recent developments regarding a habitat banking system and generic metrics to measure no net loss