Inherent and Realized Potential of Axillary Buds of White Clover in Field Populations

Fewer than 10% of while clover (Trifolium repens L.) axillary buds form established branches in grazed swards. In order to understand the mechanisms controlling his large loss of growth potential we have charted the potential fates a bud may meet. Each step in this flow chart offers the possibility for a loss of branching potential. We consider the factors that may be important in determining the fates of buds and highlight in particular the heavy losses of viable buds at a young age and propose that different factors may control branch initiation and branch establishment

Defoliation of Young Branch and Parent Stolons of White Clover in Rotationally Grazed Pastures

This study was undertaken to examine the relative severity of defoliation of young branches (those comprising \u3c4 nodes) and parent stolons of white clover (Trifolium repens L.) in rotationally grazed pastures stocked al either 2.5, 5.0 or 7.5 bulls/ha. On 7 occasions over a year, the defoliation of expanded leaves of parenl and branch stolons was assessed using tagged stolons. Petiole length of leaves ,vas measured before grazing. Leaves of young branch stolons (43% of the total number of leaves defoliated) were less severely defoliated than leaves of parent stolons (64%). Defoliation of branch stolon leaves was relatively greater at the higher stocking rates which had lower residual herbage biomasses. Before grazing, the mean petiole length of young branch leaves was only 42% that of leaves of parent stolons. It was concluded that reduced defoliation of young branch leaves resulted from their lower position in the sward and was likely to enhance the probability of survival of young branch stolons

Treatment regimens and outcomes in severe and moderate haemophilia A in the UK: The THUNDER study

Introduction: The THUNDER study provides an analysis of treatment patterns and outcomes in UK patients with severe or moderate haemophilia A (SHA/MHA) in 2015. Methods: Patients with SHA or MHA registered with the UK National Haemophilia Database (NHD) were segregated by severity, inhibitor status and age. Haemophilia joint health score (HJHS) was derived from NHD records and treatment regimen and annualized bleed/joint‐bleed rate (ABR/AJBR) from Haemtrack (HT) in HT‐compliant patients. Results: We report 1810 patients with SHA and 864 with MHA. Prophylaxis was used in 94.9% (n = 130/137) of HT‐compliant children <12 years with SHA, falling to 74.1% (n = 123/166) aged ≥40 years. Median ABR increased with age (1.0, IQR 0.0‐5.0, <12 years; 3.0 IQR, 1.0‐8.0, ≥40 years). Inhibitors were present in 159 (8.8%) SHA and 34 (3.9%) MHA. Median ABR increased from 2.0 (<12 years) to 21.(≥40 years) in SHA inhibitor patients using prophylaxis. Prophylaxis was used by 68.8% of HT‐compliant MHA patients (n = 106) (median FVIII baseline 0.01 IU/mL) associated with a median (IQR) ABR of 3.0 (1.0‐7.0). Median HJHS (n = 453) increased with age in SHA and MHA. Median (IQR) HJHS was higher in SHA inhibitor (17.0, 0.0‐64.5) than non‐ or past inhibitor patients (7.0, 0.0‐23.0). Conclusions: Increasing ABR with age persists despite current prophylaxis regimens.SHA and MHA had similar ABR/AJBR and HJHS, leading to a suspicion that a subgroup of MHA may be relatively undertreated. More intensive prophylaxis may improve outcomes, but this requires further study

Nuclear Resonance Vibrational Spectroscopy of Iron Sulfur Proteins

Nuclear inelastic scattering in conjunction with density functional theory (DFT) calculations has been applied for the identification of vibrational modes of the high-spin ferric and the high-spin ferrous iron-sulfur center of a rubredoxin-type protein from the thermophylic bacterium Pyrococcus abysii

Nonequivalence of second sphere "noncatalytic" residues in pentaerythritol tetranitrate reductase in relation to local dynamics linked to H-transfer in reactions with NADH and NADPH coenzymes

Many enzymes that catalyze hydride transfer reactions work via a mechanism dominated by quantum mechanical tunneling. The involvement of fast vibrational modes of the reactive complex is often inferred in these reactions, as in the case of the NAD(P)H-dependent pentaerythritol tetranitrate reductase (PETNR). Herein, we interrogated the H-transfer mechanism in PETNR by designing conservative (L25I and I107L) and side chain shortening (L25A and I107A) PETNR variants and using a combination of experimental approaches (stopped-flow rapid kinetics, X-ray crystallography, isotope/temperature dependence studies of H-transfer and NMR spectroscopy). X-ray data show subtle changes in the local environment of the targeted side chains but no major structural perturbation caused by mutagenesis of these two second sphere active site residues. However, temperature dependence studies of H-transfer revealed a coenzyme-specific and complex thermodynamic equilibrium between different reactive configurations in PETNR–coenzyme complexes. We find that mutagenesis of these second sphere “noncatalytic” residues affects differently the reactivity of PETNR with NADPH and NADH coenzymes. We attribute this to subtle, dynamic structural changes in the PETNR active site, the effects of which impact differently in the nonequivalent reactive geometries of PETNR−NADH and PETNR−NADPH complexes. This inference is confirmed through changes observed in the NMR chemical shift data for PETNR complexes with unreactive 1,4,5,6-tetrahydro-NAD(P) analogues. We show that H-transfer rates can (to some extent) be buffered through entropy–enthalpy compensation, but that use of integrated experimental tools reveals hidden complexities that implicate a role for dynamics in this relatively simple H-transfer reaction. Similar approaches are likely to be informative in other enzymes to understand the relative importance of (distal) hydrophobic side chains and dynamics in controlling the rates of enzymatic H-transfer

Nucleation of a sodium droplet on C60

We investigate theoretically the progressive coating of C60 by several sodium atoms. Density functional calculations using a nonlocal functional are performed for NaC60 and Na2C60 in various configurations. These data are used to construct an empirical atomistic model in order to treat larger sizes in a statistical and dynamical context. Fluctuating charges are incorporated to account for charge transfer between sodium and carbon atoms. By performing systematic global optimization in the size range 1<=n<=30, we find that Na_nC60 is homogeneously coated at small sizes, and that a growing droplet is formed above n=>8. The separate effects of single ionization and thermalization are also considered, as well as the changes due to a strong external electric field. The present results are discussed in the light of various experimental data.Comment: 17 pages, 10 figure

A deep dive into the ecology of Gamay (Botany Bay, Australia): current knowledge and future priorities for this highly modified coastal waterway

Context: Gamay is a coastal waterway of immense social, cultural and ecological value. Since European settlement, it has become a hub for industrialisation and human modification. There is growing desire for ecosystem-level management of urban waterways, but such efforts are often challenged by a lack of integrated knowledge. Aim and methods: We systematically reviewed published literature and traditional ecological knowledge (TEK), and consulted scientists to produce a review of Gamay that synthesises published knowledge of Gamay’s aquatic ecosystem to identify knowledge gaps and future research opportunities. Key results: We found 577 published resources on Gamay, of which over 70% focused on ecology. Intertidal rocky shores were the most studied habitat, focusing on invertebrate communities. Few studies considered multiple habitats or taxa. Studies investigating cumulative human impacts, long-term trends and habitat connectivity are lacking, and the broader ecological role of artificial substrate as habitat in Gamay is poorly understood. TEK of Gamay remains a significant knowledge gap. Habitat restoration has shown promising results and could provide opportunities to improve affected habitats in the future. Conclusion and implications: This review highlights the extensive amount of knowledge that exists for Gamay, but also identifies key gaps that need to be filled for effective management

Advances in ab-initio theory of Multiferroics. Materials and mechanisms: modelling and understanding

Within the broad class of multiferroics (compounds showing a coexistence of magnetism and ferroelectricity), we focus on the subclass of "improper electronic ferroelectrics", i.e. correlated materials where electronic degrees of freedom (such as spin, charge or orbital) drive ferroelectricity. In particular, in spin-induced ferroelectrics, there is not only a {\em coexistence} of the two intriguing magnetic and dipolar orders; rather, there is such an intimate link that one drives the other, suggesting a giant magnetoelectric coupling. Via first-principles approaches based on density functional theory, we review the microscopic mechanisms at the basis of multiferroicity in several compounds, ranging from transition metal oxides to organic multiferroics (MFs) to organic-inorganic hybrids (i.e. metal-organic frameworks, MOFs)Comment: 22 pages, 9 figure

Soil-landscape and climatic relationships in the middle Miocene of the Madrid Basin

The Miocene alluvial-lacustrine sequences of the Madrid Basin, Spain, formed in highly varied landscapes. The presence of various types of palaeosols allows assessment of the effects of local and external factors onsedimentation, pedogenesis and geomorphological development. In the northern, more arid, tectonicallyactive arca, soils were weakly developed in aggrading alluvial fans, dominated by mass flows. reflecting high sedimentation rates. In more distal parts of the fans and in playa lakes calcretes and dolocretes developed: the former were associated with Mg-poor fan sediments whitc: the latter formed on Mg-rich lake clays exposed during minar lake lowstands. The nonh-east part of the basin had a less arid climate. Alluvial fans in this area were dominated by stream Aood deposits, sourced by carbonate terrains. Floodplain and freshwater lakc deposits formed in distal areas. The high local supply of calcium carbonate may have contributed to the preferential developmenl on calcretes on the fans. Both the fan and floodplain palaeosols exhibit pedofacies relationships and more mature soils developed in settings more distant from the sediment sources. Palaeosols also developed on pond and lake margin carbonates, and led to the formation of palustrine limestones. The spatial distributions and stratigraphies of palaeosols in the Madrid Basin alluvial fans suggest that soil formation was controlled by local factors. These palaeosols differ from those seen in Quatemary fans. Which are characterized by climatically induced periods of stability and instability