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The influence of tidal inundation on mangrove vegetation species distribution is a key concept in mangrove ecology, and is especially important when considering the vulnerability of mangroves to predicted future sea level rise. While the tidal inundation-vegetation relationship defines a huge number of studies in mangrove science, it is not a new concept, but was mapped in the 1920s by scientists such as James Gilbert Watson, a forester with the colonial Forestry Department in Malaysia. Watson is particularly famous for his description of “Inundation Classes”, which described the flooding frequency at which different mangrove vegetation species could be found. It is interesting to consider how current paradigms and management practices (e.g. mangrove restoration) are shaped by the historical research that contributed to them. This article introduces JG Watson as a key figure in mangrove ecology, describes his seminal work on mangrove species distribution in peninsular Malaysia, and charts his legacy and contribution to current scientific debates surrounding physical controls on mangrove ecology. Importantly, research on tidal inundation and species distribution by Watson and others must be used correctly, including an acknowledgement that vegetation-inundation linkages are not universally applicable, and that species distribution is multi-factorial, and not dependent on inundation alone.

Ecosystem services have gained rapid interest for understanding urban-environment interactions. However, while the term “ecosystem services” is relatively novel, their principles have influenced urban planning for decades. This study assesses the wealth of urban ecosystem services research conducted in the tropical city state of Singapore, in particular their historical local use and implicit and explicit incorporation into land use planning, and shows how Singapore is exporting their experiences to other cities around the world. Singapore is an important model for urban ecosystem services research, as the nation has experienced rapid urban development and has a 100 % urban population. Singapore also historically utilized ecosystem services in urban decision making long before the concept was popularized. For example, forests were conserved since 1868 for climatic regulation and for the watershed protection services provided to Singapore’s first reservoirs, and green spaces have been conserved for cultural ecosystem services since the 1920s. Urban ecosystem services were formally incorporated into national planning in the 1960s through the “Garden City” urban planning vision. Singapore is now a leading case study for tropical urban climatology and carbon sequestration, exporting its experiences globally through bilateral agreements and the construction of eco-cities in China, and the creation and promotion of a global City Biodiversity Index to assess urban ecosystem service provision in cities across the globe. Consolidating and understanding case study cities such as Singapore is important if we are to understand how to incorporate multiple ecosystem services into large scale planning frameworks, and provides an important tropical example in a research field dominated by western, temperate case studies.

Mangroves are one of the most carbon‐dense forests on the Earth and have been highlighted as key ecosystems for climate change mitigation and adaptation. Hundreds of studies have investigated how mangroves fix, transform, store, and export carbon. Here, we review and synthesize the previously known and emerging carbon pathways in mangroves, including gains (woody biomass accumulation, deadwood accumulation, soil carbon sequestration, root and litterfall production), transformations (food web transfer through herbivory, decomposition), and losses (respiration as CO2 and CH4, litterfall export, particulate and dissolved carbon export). We then review the technologies available to measure carbon fluxes in mangroves, their potential, and their limitations. We also synthesize and compare mangrove net ecosystem productivity (NEP) with terrestrial forests. Finally, we update global estimates of carbon fluxes with the most current values of fluxes and global mangrove area. We found that the contributions of recently investigated fluxes, such as soil respiration as CH4, are minor (<1 Tg C year−1), while the contributions of deadwood accumulation, herbivory, and lateral export are significant (>35 Tg C year−1). Dissolved inorganic carbon exports are an order of magnitude higher than the other processes investigated and were highly variable, highlighting the need for further studies. Gross primary productivity (GPP) and ecosystem respiration (ER) per area of mangroves were within the same order of magnitude as terrestrial forests. However, ER/GPP was lower in mangroves, explaining their higher carbon sequestration. We estimate the global mean mangrove NEP of 109.1 Tg C year−1 (7.4 Mg C ha−1 year−1) or through a budget balance, accounting for lateral losses, a global mean of 66.6 Tg C year−1 (4.5 Mg C ha−1 year−1). Overall, mangroves are highly productive, and despite losses due to respiration and tidal exchange, they are significant carbon sinks.

Small molecule effectors regulate gene transcription in bacteria by altering the DNA-binding affinities of specific repressor proteins. Although the GntR proteins represent a large family of bacterial repressors, only little is known about the allosteric mechanism that enables their function. DasR from Streptomyces coelicolor belongs to the GntR/HutC subfamily and specifically recognises operators termed DasR-responsive elements (dre-sites). Its DNA-binding properties are modulated by phosphorylated sugars. Here, we present several crystal structures of DasR, namely of dimeric full-length DasR in the absence of any effector and of only the effector-binding domain (EBD) of DasR without effector or in complex with glucosamine-6-phosphate (GlcN-6-P) and N-acetylglucosamine-6-phosphate (GlcNAc-6-P). Together with molecular dynamics (MD) simulations and a comparison with other GntR/HutC family members these data allowed for a structural characterisation of the different functional states of DasR. Allostery in DasR and possibly in many other GntR/HutC family members is best described by a conformational selection model. In ligand-free DasR, an increased flexibility in the EBDs enables the attached DNA-binding domains (DBD) to sample a variety of different orientations and among these also a DNA-binding competent conformation. Effector binding to the EBDs of DasR significantly reorganises the atomic structure of the latter. However, rather than locking the orientation of the DBDs, the effector-induced formation of β-strand β* in the DBD-EBD-linker segment merely appears to take the DBDs 'on a shorter leash' thereby impeding the 'downwards' positioning of the DBDs that is necessary for a concerted binding of two DBDs of DasR to operator DNA.

Antigen binding to B-cell antigen receptors (BCRs) followed by signaling initiates the humoral immune response. The signaling is intimately coupled to nanoclustering of BCRs and their sorting to specific membrane domains, a process that is ruled by interactions between the BCR transmembrane domain and lipids. While the structure of the extracellular domains of BCRs has been resolved, little is known about the configuration of the constituting four immunoglobulin domains spanning the membrane. Here, we modeled the structure of the transmembrane (TM) domain of the IgM B-cell receptor using self-assembly coarse-grained molecular dynamics simulations. The obtained quaternary structure was validated against available experimental data and atomistic simulations. The IgM-BCR-TM domain configuration shows a 1:1 stoichiometry between the homodimeric membrane-bound domain of IgM (mIgM) and a Ig-α/Ig-β heterodimer. The mIgM homodimer is based on an asymmetric association of two mIgM domains. We show that a specific site of the Ig-α/Ig-β heterodimer is responsible for the association of IgM-BCRs with lipid rafts. Our results further suggest that this site is blocked in small-sized IgM-BCR clusters. The BCR TM structure provides a molecular basis for the previously suggested dissociation activation model of B-cell receptors. Self-assembly molecular dynamics simulations at the coarse-grained scale here proved as a versatile tool in the study of receptor complexes.

SummaryThe paper focuses on the identification of atypical fractures (AFFs). This paper examines the concordance between objective classification and expert subjective review. We believe the paper adds critical information about how to apply the American Society of Bone and Mineral Research (ASBMR) criteria to diagnose AFFs and is of high interest to the field.IntroductionAssess American Society of Bone and Mineral Research (ASBMR) criteria for identifying atypical femoral fractures (AFFs).MethodsTwo orthopedic surgeons independently evaluated radiographs of 372 fractures, applying ASBMR criteria. We assessed ease of applying ASBMR criteria and whether criteria-based assessment matched qualitative expert assessment.ResultsThere was up to 27% uncertainty about how to classify specific features. 84% of films were classified similarly for the presence of AFF according to ASBMR criteria; agreement increased to 94% after consensus meeting. Of 37 fractures categorized as AFFs based on ASBMR criteria, 23 (62.2%) were considered AFFs according to expert assessment (not relying on criteria). Only one (0.5%) femoral shaft fracture that did not meet ASBMR criteria was considered an AFF per expert assessment. The number of major ASBMR features present (four vs five) and whether there was periosteal or endosteal thickening (“beaking” or “flaring”) played major roles in the discrepancies between ASBMR criteria-based and expert-based determinations.ConclusionsASBMR AFF criteria were useful for reviewers but several features were difficult to interpret. Expert assessments did not agree with the ASBMR classification in almost one-third of cases, but rarely identified an AFF when a femoral shaft fracture did not meet ASBMR AFF criteria. Experts identified lateral cortical transverse fracture line and associated new-bone formation along with no or minimal comminution as crucial features necessary for the definition of atypical femoral fractures.

Scientific evidence will be better incorporated into conservation action and environmental policy if it is deemed credible by decision-makers. However, huge uncertainties are inherent in large-scale ecosystem statistics. Two wetland case studies relating to mangrove areal extent in Peninsular Malaysia and saltmarsh loss in the UK indicate the major causes of information uncertainty, relating to poor methodological description, traceability and assumptions associated with the use of grey literature. Furthermore, potentially inaccurate information can be propagated throughout the research community and gain ‘proof by assertion’, especially if the information originates from an authoritative source. Researchers must better consider implicit and explicit uncertainty and be critical of secondary information. Future information production requires the use of rigorous peer-reviewed methodologies in order to decrease and quantify error. Such steps will increase the credibility of scientific evidence, so researchers can better contribute to a two-way science and policy deliberation approach.

The mechanisms of the reduction of Cu(II) in matrix-assisted laser desorption/ionization mass spectrometry (MALDI) are studied. In MALDI mass spectra, ions cationized by copper mostly contain Cu(I) even if Cu(II) salts are added to the sample. It was found that Cu(II) was reduced to Cu(I) by gas-phase charge exchange with matrix molecules, which is a thermodynamically favorable process. Under some conditions, large amounts of free electrons are present in the plume. Cu(II) can be even more efficiently reduced to Cu(I) by free electron capture in the gas phase. The matrices studied in this work are nicotinic acid, dithranol, and 2,5-dihydroxybenzoic acid.

Summary Bisphosphonate therapy reduces fracture risk but does not eliminate fracture occurrence. We determined the fracture incidence and risk factors for fractures among 14,674 bisphosphonate users in a community setting. Bisphosphonate users remained at risk of fracture, and additional measures to prevent fractures in these patients would be beneficial. Introduction Bisphosphonate therapy reduces but does not eliminate fracture occurrence. The incidence of fracture and risk factors for fractures among persistent, current users of bisphosphonates in a community setting have not been well studied. Methods We conducted a retrospective cohort study of 14,674 bisphosphonate users in a health maintenance organization. Patients were followed until a 3-month gap in therapy, creating a pool of highly compliant [mean medication possession ratio (MPR) of 94 %] current users. We used Cox proportional hazards models to identify risk factors for fractures among these persistent, current users. Results There were 867 fractures over the period of observation or 3.7 fractures per 100 users per year. Older patients who take multiple medications, have lower bone mineral density, have a history of prior fracture, and suffer from particular comorbidities (i.e., dementia, chronic kidney disease, and rheumatoid arthritis) are at higher risk of fracture while taking bisphosphonates. Conclusion Persistent, current bisphosphonate users remain at risk of fracture, and additional measures to prevent fractures in these patients would be of benefit.

Quantification of processes contributing to overall surface elevation change is critical to the accurate assessment of saltmarsh sedimentary status, particularly when predicting system stability in relation to accelerated sea level rise. Rates of short-term (up to 5.5 years) surface elevation change and accretion on a temperate saltmarsh were measured at an open coast managed realignment (habitat creation) trial, and the surrounding intertidal zone using surface elevation table–marker horizon (accretion plate) methodologies. Mean surface elevation changes on vegetated saltmarsh control sites, at some distance from the hydrodynamic disturbance of breaches in a former sea defence line, showed rates of change compatible with marsh surface dynamics seen elsewhere in the region, exceeding rates of regional relative sea-level rise. Within the managed realignment, sites close to the breaches showed exceptionally high rates of both accretion and surface elevation change, most likely as a result of high localized sediment supply from breach and channel enlargement and the presence of surfaces left unnaturally low in the tidal frame. Positive surface elevation change on the landward side of the breaches reached >30.4 mm a −1 , up to one hundred times greater than rates of surface elevation change at locations 1 km from the breach entrances. Shallow sub-surface processes, or ‘surface subsidence’, was an important process on natural marshes outside the managed realignment but not seen within the site, due to the consolidated nature of the underlying substrate. The Freiston Shore managed realignment site shows remarkably similar time variation in mean elevation to that of the longer record from the Tollesbury managed realignment site, Blackwater estuary, Essex coast, UK. It is not clear how long it will take for re-created intertidal habitats at both Freiston Shore and Tollesbury to approach an ‘equilibrium’ elevation within the tidal frame but modelling suggests that in natural wetlands on the coast of eastern England this process takes at least 150 years.