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.
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.
► Even win–win REDD+ interventions can face biodiversity and carbon trade-offs. ► Biodiversity outcomes are functions of geographic targeting and activity selection. ► Funding is likely to determine ...whether biodiversity is integrated into REDD+.
Recent practise has revealed that conservation interventions that seek to achieve multiple benefits generally face significant, if under-recognized trade-offs. REDD+ policies present prospective win–win solutions for climate change mitigation, rural development and biodiversity conservation. Notably, protecting, enhancing and restoring forests for their carbon sequestration services has the potential to additionally promote the conservation of imperiled tropical biodiversity. However, it has become increasingly apparent that efforts to design a REDD+ mechanism that optimizes emissions reductions and associated co-benefits face significant environmental and economic trade-offs. We provide a framework for conceptualizing the major related policy options, presenting the associated trade-offs as a continuum and as functions of two key factors: (1) geographic targeting, and (2) the selection of specific forest management activities. Our analysis highlights the challenges of assessing trade-offs using existing data and valuation schemes, and the difficulty of paying for and legislating biodiversity co-benefits and safeguards within a future REDD+ mechanism.
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.
Summary
The 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.
Introduction
Assess American Society of Bone and Mineral Research (ASBMR) criteria for identifying atypical femoral fractures (AFFs).
Methods
Two 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.
Results
There 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.
Conclusions
ASBMR 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.
The goal of this trial was to determine whether coronal plane angulation affects functional and clinical outcomes after the fixation of distal femur fractures.
Multicenter, randomized controlled ...trial
20 academic trauma centers
156 patients with distal femur fractures were enrolled. 123 patients were followed 12 months. There was clinical outcome data available for 105 patients at 3 months, 95 patients at 6 months and 81 patients at one year.
Lateral locked plating or retrograde intramedullary nailing
Radiographic alignment, functional scoring including SMFA, Bother Index, and EQ-5D. Clinical scoring of walking ability, need for ambulatory support and ability to manage stairs.
At 3 months, there was no difference between groups (varus, neutral or valgus) with respect to any of the clinical functional outcome scores measured. At 6 months, compared to those with neutral alignment, patients with varus angulation had a worse Stair Climbing score (4.33 vs. 2.91, p = 0.05). At 12 months, the average patient with neutral or valgus alignment needed less ambulatory support than the average patient in varus. Walking distance ability was no different between the groups at any time point.
With respect to the validated patient-based outcome scores, we found no statistical difference in in the SMFA, Bother, or EQ-5D between patients with valgus or varus mal-alignment and those with neutral alignment at any time point (p > 0.05). Regardless of coronal angulation, the SMFA trended towards lower (improved) scores over time, while EQ-5D scores for patients with varus angulation did not improve over time.
Valgus angulation and neutral angulation may be better tolerated in terms of clinical outcomes like stair climbing and need for ambulatory support than varus angulation, though patient reported outcome measures like the SMFA, Bother Index and EQ-5D show no statistical significance. Most patients with distal femur fractures tend to improve during the first year after injury but many remain significantly affected at 12 months post injury.
•Surface elevation is a key control on mangrove seedling distribution.•Seedlings established at an elevation range of −1.255m to 0.228m WGS 84.•Increasing surface elevation in ponds will facilitate ...seedling establishment.•Mapping site surface elevation can optimise rehabilitation design and success.
Intertidal mangrove forests are declining rapidly in Southeast Asia due to diverse threats such as urbanisation, agriculture and aquaculture. Mangrove rehabilitation programmes designed to compensate for such declines are largely unsuccessful as they fail to match environmental conditions to species-specific tolerance thresholds for different mangrove vegetation species. This study investigated the importance of surface elevation (related to tidal inundation period) in influencing the colonisation and establishment of mangroves in a rehabilitation site in Sulawesi, Indonesia. A topographic survey of 29 abandoned aquaculture ponds was conducted to map the surface elevations before and shortly after rehabilitation. A vegetation survey was conducted in a neighbouring reference forest to quantify the surface elevation envelopes of established mangroves, and in the rehabilitated site to predict where successful vegetation establishment would occur, and to guide remedial works to make surface elevations suitable for establishment. Surface elevations in aquaculture ponds ranged between −2.158m and 2.411m WGS 84. 651 mangrove individuals across 13 species had established naturally in ponds within six months after rehabilitation, and were restricted to elevations of −1.511m to 0.228m WGS 84. Seedlings/saplings from both ponds and reference forests had established at comparable surface elevation ranges of −1.511m to 0.228m WGS 84 and −1.255m to 0.073m WGS 84. The elevation envelope occupied by seedlings in aquaculture ponds was widest for Avicennia rumphiana (−1.085m to −0.218m WGS 84) and in reference forests, Rhizophora mucronata (−0.850m to −0.503m WGS 84). This study highlights the importance of intertidal surface elevation and its control on inundation hydroperiod as a key, spatially explicit threshold to seedling colonisation establishment. The rehabilitation of appropriate surface elevations is a crucial first step in successful mangrove rehabilitation.
PDF
