1,386 research outputs found
Protein glycosylation as a diagnostic and prognostic marker of chronic inflammatory gastrointestinal and liver diseases
Glycans are sequences of carbohydrates that are added to proteins or lipids to modulate their structure and function. Glycans modify proteins required for regulation of immune cells, and alterations have been associated with inflammatory conditions. For example, specific glycans regulate T-cell activation, structures, and functions of immunoglobulins; interactions between microbes and immune and epithelial cells; and malignant transformation in the intestine and liver. We review the effects of protein glycosylation in regulation of gastrointestinal and liver functions, and how alterations in glycosylation serve as diagnostic or prognostic factors, or as targets for therapy
Modelling Grazing and Burning in Communal Rangelands to Help Understand Trade-offs between Production, Carbon, and Water
Rangelands cover more than 80% of South Africa’s land area, providing critical ecosystem services, livelihoods and cultural values related to livestock. Communally owned rangelands are often overgrazed and subject to runaway fires but lack of data limits our understanding of how these threats impact production. In this transdisciplinary project, we use models to test hypotheses and predict future scenarios as a planning tool for resource-poor communal farmers. We think that moderate grazing and fire regimes will increase overall production and carbon sequestration with uncertain trade-offs for water and nutrient cycling. To test this, we trained two process-based biogeochemical models (DAYCENT and SPACSYS) with individual merits to simulate known fire returns and grazing pressures on a 40-year old long-term ecological research grassland site, and validated models with data from Mvenyane, a nearby communal livestock grazing area. DAYCENT and SPACSYS simulated observed soil organic carbon well, while accuracy for aboveground herbaceous biomass differed between models. DAYCENT projected that soil organic carbon could increase by ca. 1000 g C m-2 over ten years or 1 t C ha-1 yr-1 with moderate increases in biomass and no change in water fluxes when changing from continuous high pressure to moderate pressure grazing in a two-camp rotation, with or without fire. These and other scenarios, including future climate projections, will be used to evaluate biophysical and social trade-offs so that sustainable land use plans can be created in Mvenyane and the wider rangeland community
Crystal structure of Enterobacter cloacae 908R class C beta-lactamase bound to iodo-acetamido-phenyl boronic acid, a transition-state analogue
peer reviewedThe structures of the, class C beta-lactamase from Enterobacter cloacae 908R alone and in complex with a baronic acid transition-state analogue were determined by X-ray crystallography at 2.1 and 2.3 Angstrom, respectively. The structure of the enzyme resembles those of other class C beta-lactamases. The structure of the. complex with the transition-state analogue, iodo-acetamido-phenyl boronic acid, shows that the inhibitor is covalently, bound to the active-site serine (Ser64). Binding of the inhibitor within the active site is compared with previously determined structures of complexes with other class C enzymes. The structure of the boronic acid adduct indicates ways to improve the affinity of this class of inhibitors. This structure of 908R class C beta-lactamase in complex with a transitionstate analogue provides further insights into the mechanism of action of these hydrolases
A class of Poisson-Nijenhuis structures on a tangent bundle
Equipping the tangent bundle TQ of a manifold with a symplectic form coming
from a regular Lagrangian L, we explore how to obtain a Poisson-Nijenhuis
structure from a given type (1,1) tensor field J on Q. It is argued that the
complete lift of J is not the natural candidate for a Nijenhuis tensor on TQ,
but plays a crucial role in the construction of a different tensor R, which
appears to be the pullback under the Legendre transform of the lift of J to
co-tangent manifold of Q. We show how this tangent bundle view brings new
insights and is capable also of producing all important results which are known
from previous studies on the cotangent bundle, in the case that Q is equipped
with a Riemannian metric. The present approach further paves the way for future
generalizations.Comment: 22 page
A randomised controlled trial comparing graded exercise treatment and usual physiotherapy for patients with non-specific neck pain (the GET UP neck pain trial).
Evidence supports exercise-based interventions for the management of neck pain, however there is little evidence of its superiority over usual physiotherapy. This study investigated the effectiveness of a group neck and upper limb exercise programme (GET) compared with usual physiotherapy (UP) for patients with non-specific neck pain. A total of 151 adult patients were randomised to either GET or UP. The primary measure was the Northwick Park Neck pain Questionnaire (NPQ) score at six weeks, six months and 12 months. Mixed modelling identified no difference in neck pain and function between patients receiving GET and those receiving UP at any follow-up time point. Both interventions resulted in modest significant and clinically important improvements on the NPQ score with a change score of around 9% between baseline and 12 months. Both GET and UP are appropriate clinical interventions for patients with non-specific neck pain, however preferences for treatment and targeted strategies to address barriers to adherence may need to be considered in order to maximise the effectiveness of these approaches
Molecular Reclassification of Crohn's Disease by Cluster Analysis of Genetic Variants
Background Crohn's Disease (CD) has a heterogeneous presentation, and is typically classified according to extent and location of disease. The genetic susceptibility to CD is well known and genome-wide association scans (GWAS) and meta-analysis thereof have identified over 30 susceptibility loci. Except for the association between ileal CD and NOD2 mutations, efforts in trying to link CD genetics to clinical subphenotypes have not been very successful. We hypothesized that the large number of confirmed genetic variants enables (better) classification of CD patients. Methodology/Principal Findings To look for genetic-based subgroups, genotyping results of 46 SNPs identified from CD GWAS were analyzed by Latent Class Analysis (LCA) in CD patients and in healthy controls. Six genetic-based subgroups were identified in CD patients, which were significantly different from the five subgroups found in healthy controls. The identified CD-specific clusters are therefore likely to contribute to disease behavior. We then looked at whether we could relate the genetic-based subgroups to the currently used clinical parameters. Although modest differences in prevalence of disease location and behavior could be observed among the CD clusters, Random Forest analysis showed that patients could not be allocated to one of the 6 genetic-based subgroups based on the typically used clinical parameters alone. This points to a poor relationship between the genetic-based subgroups and the used clinical subphenotypes. Conclusions/Significance This approach serves as a first step to reclassify Crohn's disease. The used technique can be applied to other common complex diseases as well, and will help to complete patient characterization, in order to evolve towards personalized medicine. </sec
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