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

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

Dependency Modelling for Cultural Heritage

May 31st - June 3rd, 200

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-μ-chloridebis[(η5-(Sp)-2-(N,N-dimethylaminomethyl)cyclopentadienyl,1-C,3′-N)(η4-tetraphenylcyclobutadiene)cobalt]dipalladium [(Sp)-Me2-CAP-Cl] in 92 % ee and 64 % yield. Enantiopurity (>98 % 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 78 % ee). The (R)-N-acetylphenylalanine mediated palladation methodology was applicable also to the corresponding N,N-diethyl (82 % ee, 39 % yield) and pyrrolidinyl (>98 % ee, 43 % yield) cobalt sandwich complexes. A combination of 5 mol % of the latter [(Sp)-Pyrr-CAP-Cl] and AgNO3 (3.8 equiv) is a catalyst for the allylic imidate rearrangement of an (E)-N-aryltrifluoroacetimidate (up to 83 % ee), and this catalyst system is also applicable to the rearrangement of a range of (E)-trichloroacetimidates (up to 99 % ee). This asymmetric efficiency combined with the simplicity of catalyst synthesis provides accessible solutions to the generation of non-racemic allylic amine derivatives

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

Pollution and cardiovascular health in Malta : a review

The leading cause of global mortality is cardiovascular disease (CVD) and in 2016 alone over 17 million premature deaths were attributed to CVD.1 Whilst previously there was only weak evidence to suggest an association of air pollution as a risk factor for CVD2, in recent years, the impact of air pollution has emerged as an independent, strong and modifiable risk factor for CVD. The importance of air pollution on CVD is now being considered above other more traditional factors such as high cholesterol and reduced physical activity.3 Exposure to fine particulate matter has been shown to increase the risk of acute coronary syndromes, yet more concerning are the studies which have shown the greater extent of its effects over a longer period of time, reducing life-expectancy by a number of years and being responsible for 19% of cardiovascul­­ar mortality (>3 million deaths).1 The purpose of this review is to identify significant studies investigating air pollution and its effects on cardiovascular health while also considering our situation in Malta, as a small, highly populated country.peer-reviewe

A case of metastatic Wilms’ tumour with reversible distortion of mediastinal anatomy : a diagnostic challenge for the echocardiographer

Delineation and documentation of anatomy in the presence of significant mass pathology presents a diagnostic challenge. This often necessitates the implementation of more than one imaging modality in order to perform an adequate assessment. We present a three-year old boy with extensive distortion of mediastinal anatomy secondary to pleural metastases from a Wilms tumour. This limited the ability to accurately assess mediastinal anatomy and cardiac function at baseline. Reassessment following initiation of chemotherapy showed a significant reduction in size of metastases with complete resolution of the mediastinal distortion.peer-reviewe

Factors influencing external audit fees in Malta

The main objective of this study is to investigate factors influencing the external audit fees in Malta. This includes assessing whether client size, complexity and risk, also known as the ―traditional‖ determinants, are applicable in the case of Malta, as well as testing the issue of premium pricing amongst the Big 4 audit firms. Of particular interest is the determination of specific factors relevant to such a market. A GLM regression model is used to examine the effect of the independent factors on the amount of audit fees for a sample of audit engagements performed in the Maltese audit market. The model is further complemented by a series of semi-structured interviews with audit partners from various audit firms of different sizes. Results indicate that the amount of external fees is significantly influenced by audit client size, complexity, risk, ownership control and corporate status. Additionally a fee premium has been found to accrue to the Big 4 audit firms.peer-reviewe