1,370 research outputs found
Representation and intervention: The symbiotic relationship of conservation and value
Physical and intellectual access to heritage is shaped by conservation through a longterm,
cyclic and symbiotic relationship of representation and intervention (or lack of
it). This informs future use and representation. Value (which may be assigned for
different reasons) makes heritage. All heritage is valued for varied reasons. Some
argue that heritage has inherent value; this is not covered in this paper. Some values
are preferred over others in decisions on what to use or conserve. The process below
describes a number of different recurring phases in this relationship, which differs
with different kinds of heritage: 1. Various agents change heritage; 2. Change affects
valued elements of heritage; 3. Valued elements affect how change is perceived; 4.
What is perceived as damage affects decisions about conservation interventions; 5.
Conservation affects which valued elements are most likely to be preserved; 6.
Preserved elements influence how heritage is represented; 7. New forms of
representation will affect future conservation decisions.
Historically, how heritage has been represented has affected how an object is
preserved. This affects later representation and use, making the relationship
symbiotic
Serpins : form, function and dysfunction
The serpin superfamily of serine protease inhibitors is one of the most ubiquitous and successful classes of inhibitors in the living world. Their unique mechanism of suicide inhibition has led to much research and several important discoveries. They function via rapid incorporation of a reactive centre loop (RCL) within a ÎČ-sheet following the former's proteolysis by the target protease: the serpin thus achieves a conformation which is more stable than the native form. Through this conformational change, the target protease structure is distorted and its function disrupted. Alpha-1-antitrypsin (AAT) has often been studied as an archetype for the serpin superfamily, and is discussed in more detail in this review. Of particular interest are the mutant variants of AAT, which have a tendency to polymerise, and thus offer insights into some mechanisms of serpin polymerisation.peer-reviewe
Reviewing past environments in a historic house using building simulation
This paper reviews different heatingregimes applied to the same space,using building simulation. Theconstruction of a computer simulationmodel to investigate past and presentenvironments in a historic house libraryis described. The model simulated fourhypothetical scenarios, based on realdata. The simulation outputs werereviewed in terms of the risk ofphysical and chemical deterioration,and their relationship with an existingnational standard for archives. Thepossibility of simulating pastenvironments to investigate naturalageing is also discussed
Autoxidation of lipids in parchment
Historic parchment is a macromolecular material, which is complex due to its natural origin, inhomogeneity of the skin structure, unknown environmental history and potential localised degradation. Most research into its stability has so far focussed on thermal and structural methods of analyses.
Using gas chromatographic analysis of the atmosphere surrounding parchment during oxidation, we provide the experimental evidence on the production of volatile aldehydes, which can be the products of lipid autoxidation. Oxidation of parchment with different aldehyde emissions was additionally followed in situ using chemiluminometry and the same techniques were used to evaluate the oxidation of differently delipidised parchment. It was shown that the production of peroxides and the emission of aldehydes from the material decrease with lower lipid content. Building on this evidence, we can conclude that the presence of lipids (either initially present in the skin or resulting from conservation intervention) leads to oxidative degradation of collagen and that the non-destructive analysis of the emission of volatiles could be used as a quick tool for evaluation of parchment stability
Enantioselective synthesis and application to the allylic imidate rearrangement of amine-coordinated palladacycle catalysts of cobalt sandwich complexes
The reaction of (η5-(N,N-dimethylaminomethyl)cyclopentadien-yl)(η4-tetraphenylcyclobutadiene)cobalt with sodium tetrachloropalladate and (R)-N-acetylphenylalanine gave planar chiral palladacycle di-ÎŒ-chloridebis[(η5-(Sp)-2-(N,N-dimethylaminomethyl)cyclopentadienyl,1-C,3âČ-N)(η4-tetraphenylcyclobutadiene)cobalt]dipalladium [(Sp)-Me2-CAP-Cl] in 92â% ee and 64â% yield. Enantiopurity (>98â% ee) was achieved by purification of the monomeric (R)-proline adducts and conversion back to the chloride dimer. Treatment with AgOAc gave (Sp)-Me2-CAP-OAc which was applied to asymmetric transcyclopalladation (up to 78â% ee). The (R)-N-acetylphenylalanine mediated palladation methodology was applicable also to the corresponding N,N-diethyl (82â% ee, 39â% yield) and pyrrolidinyl (>98â% ee, 43â% yield) cobalt sandwich complexes. A combination of 5â
molâ% of the latter [(Sp)-Pyrr-CAP-Cl] and AgNO3 (3.8â
equiv) is a catalyst for the allylic imidate rearrangement of an (E)-N-aryltrifluoroacetimidate (up to 83â% ee), and this catalyst system is also applicable to the rearrangement of a range of (E)-trichloroacetimidates (up to 99â% ee). This asymmetric efficiency combined with the simplicity of catalyst synthesis provides accessible solutions to the generation of non-racemic allylic amine derivatives
Chondral Lesion in the Hip Joint and Current Chondral Repair Techniques
This chapter gives a detailed review of the composition, structure and biomechanics of articular cartilage in the joint. W have looked at the most common types of cartilage lesions and at the existing methods of articular cartilage repair techniques in the hip joint. Articular cartilage is specialized hyaline cartilage which makes a firm, smooth and slippery surface that resists plastic deformation. It has a unique structure and mechanical properties that provide joints with a surface that combines low friction, shock absorption and wear resistance, while bearing large repetitive loads throughout an individualâs lifetime. Cartilage lesions in the hip are most common on the acetabular side and typically present as focal area of delamination or chondral flap. Joint preserving techniques are becoming increasingly common. The spectrum of options includes palliative procedures such as joint lavage and chondral debridement, reparative procedures such as microfracture and direct chondral repair, and restorative procedures such as mosaicoplasty. Preservation of the host tissue is most attractive solution to cartilage damage, particularly in young active individuals. Tissue engineering offers one solution but many problems have to be overcome before these techniques become a reality
Emission of reactive oxygen species during degradation of iron gall ink
Iron gall inks are characterised by high contents of acids and transition metals, promoting degradation of cellulose due to hydrolysis and oxidation, respectively. Their chemical interaction with the environment is not well understood, especially in view of emissions of degradation products which could lead to spread of degradation processes.
In order to study the emissions, we employed gas chromatography/mass spectrometry following headspace micro-extraction, and liquid chromatography following hydroxyl radical scavenging with appropriate probes. We also studied chemiluminescence of cellulose affected by ink degradation.
We show that while the emissions of organic volatile degradation compounds by inks are less intense than those of surrounding paper, ink does promote the degradation of cellulose across big distances (from object to object). We were able to link this to emission of reactive oxygen species, probably hydrogen peroxide. Its emission from ink is considerably more intensive than from paper
The combined honours student experience survey data and the perceptions of staff and students
Data analysis from the University Student Survey (2016) at Canterbury Christ Church University revealed that combined honours students (n=780) were less satisfied than single honours students. The qualitative comments of the students referred to concerns about identifying with and belonging to the programme; and self confidence. In addition, on one programme (n=89), combined honours student were less satisfied than their single honours classmates on 18 of the 22 USS satisfaction measure statements.
Three focus group with staff on this programme (n=18) and interviews with students (n=8) were undertaken to investigate the issues of lack of satisfaction further.
This paper will report on the ongoing investigation and the potential development of learning and teaching interventions
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