1,722,685 research outputs found
Bioaerosol
No full textCultural heritage constitutive materials can provide excellent substrates for microbial colonisation, highly influenced by thermo-hygrometric parameters. In cultural heritage-related environments, a detrimental microbial load may be present both on artworks surface and in the aerosol. Confined environments (museums, archives, deposits, caves, hypogea) are characterised by peculiarstructures and different thermo-hygrometric conditions, influencing the development of a wide range of microbial species, able to induce artefact biodeterioration and to release biological particles in the aerosol (spores, cellular debrides, toxins, allergens) potentially dangerous for the human health (visitors/users). In order to
identify the real composition of the biological consortia, highlighting also the symbiotic relationships between microorganisms (cyanobacteria, bacteria, fungi) and macro-organisms (plants, bryophyte, insects), an interdisciplinary approach is needed.
The results from in vitro culture, microscopy and molecular biology analysis are essential for a complete understanding of both microbial colonisation of the cultural objects and the potential relationship with illness to human. Concerning the bioaerosol, of crucial importance are the time and techniques for sampling
14.9 ANALYTICAL TECHNIQUES
No full textAn analytical technique is a method that is used to determine the value of a certain
characteristic of the material, for example the amount of a chemical compound or the
concentration of chemical elements. There is a wide variety of techniques used for
analysis, from a simple analytical balance to very advanced techniques using highly
specialized instrumentations. As an example, the most common techniques used in
analytical chemistry are listed in Figure 14.1.
The analytical techniques are characterized by their invasiveness, type of information
supplied, physical state of the sample, being portable or not, resolution, how much sample
it needs, expression of the result, what materials can be analyzed, costs of instrumentation
and analysis.
The contribution given by analytical investigation to the cultural heritage knowledge can
be related to:
- technological information,
- provenance studies,
- conservation and restoration,
- dating or authentication of a finding.
Some examples have been shown in the previous chapter
Biotechnology and Conservation of Cultural Heritage
No full textOver the past few decades, biotechnology has provided innovative techniques useful for diagnosing cultural heritage deterioration induced by microbiological systems and for defining efficient conservation/restoration strategies. Seen from this per- spective, the International Congress on Molecular Biology and Cultural Heritage held in Seville (Spain) in 2003 represents a milestone.
This book comes from the experience gained in the last decade of basic and applied research, developed in the Laboratory of Biology and Biotechnology for Cultural Heritage (LaBBCH), within the framework of national and international research projects and in collaboration with other Italian and foreign research institu- tions. In particular, biotechnology has found successful application in at least three areas in the conservative restoration of works of art, such as the characterization of biodeterioration, the analysis of bioaerosols, and the development of innovative protocols for biocleaning and bioremoval.
A biotechnological approach to biodeterioration minimizes sample amount, con- tributing to understanding the contamination and complexity of microbial commu- nities colonizing the cultural assets, as well as revealing unculturable species in both organic and inorganic substrates. This approach, based on genomic DNA analysis, has also proven useful in recognizing microbial systems in the aerosol of indoor cultural heritage environments, particularly for those representing a potential health risk for visitors and professionals.
It is well known that the removal of undesired layers can be performed by viable bacterial cells or purified enzymes (hydrolases), thus contributing to the develop- ment and definition of specific biocleaning/bioremoving protocols. The application of novel bioactive molecules isolated from marine organisms has recently been employed, opening up new perspectives for the enzymatic removal of undesired layers.
This book also presents the use of plant extracts, already utilized as a biocide in the food, medicine, and pharmaceutical industries, as a strategy for controlling the microbial colonization of cultural heritage, representing a potential alternative to traditional biocides.
There is no doubt that biotechnology provides a plethora of information useful for setting up appropriate strategies that are totally safe for works of art, restorers, and environment, and require only a short time of application, straight to green conservation strategies in a sustainable restoration prospective.
Case studies are reported in the final chapter in order to demonstrate that a bio- technological approach may represent a valid alternative to traditional procedures generally used in the conservation/restoration of cultural assets.
In this book, I have tried to present current knowledge in the field, highlighting the extraordinary power of DNA and of the novel bioactive molecules when applied to the conservative restoration of cultural assets. I apologize to the authors of those papers who have escaped my attention, and also to those whose papers I have not quoted accurately
A search for clustering around Herbig Ae/Be stars. II. Atlas of the observed sources
No full textWe present large field infrared images of a sample of 45 Herbig Ae/Be stars. Stellar parameters, such as age and luminosity, have been derived for all of them in a consistent way. The images have been used to identify stellar groups or clusters associated with the Herbig Ae/Be star. The results presented in this paper form the database for a study of clustering around intermediate mass stars (Testi et al. 1998)
FRESHWATER CYANOBACTERIA, IDENTIFIED BY MICROSCOPIC AND MOLECULAR INVESTIGATIONS ON A COLONIZED FOUNTAIN SURFACE: A CASE STUDY IN PALERMO (SICILY, ITALY)
Full text linkCyanobacteria or blue algae are ubiquitously present in both fresh and brackish water
environments. They also grow in conditions of high humidity, colonizing stones or
monuments and fountain surfaces, and creating thick biofilms able to induce biodeterioration
in the constituent materials of artefacts. As well as several photoautotrophic
organisms, cyanobacteria belong to the microorganisms identified as primary colonizers,
playing an important role in stone artwork deterioration.
In this study, an analysis was made of the biofilm collected from the stone fountain of
the Two Dragons in Palermo (Italy), revealing the presence of cyanobacterial colonies by
optical microscopy, due to their peculiar auto-fluorescence. Furthermore, molecular investigations
by qPCR (quantitative Polymerase Chain Reaction) were utilized to gather
quantitative information, and phylogenetics analysis was used to confirm the Thioredoxin
reductase (TrxR) gene as a suitable molecular marker. The results highlight the presence
of cyanobacteria as the main taxa, whose growth is induced by microclimatic and
environmental conditions, and by the physical characteristics of the stone surface.
Identification of microbial populations living on stone artworks is the starting point for
successful control and conservation strategies, which can help to define the correct
protocols to block cellular activity and to find appropriate methods for removing biofilm,
as well as counteracting possible recolonization
The onset of cluster formation around Herbig Ae/Be stars
No full textThe large body of near infrared observations presented in Testi et al. ( te{Tea97}; te{Tea98}) are analysed with the aim of characterizing the young stellar clusters surrounding Herbig Ae/Be stars. The results confirm the tendency of early Be stars to be surrounded by dense clusters of lower mass ``companions'', while Ae stars are never found to be associated with conspicuous groups. The transition between the different environments appears to occur smoothly from Ae to Be stars without a sharp threshold. No correlation of the richness of the stellar groups detected is found with the galactic position or the age of the central Herbig Ae/Be star. The stellar volume densities estimated for the groups surrounding pre-main-sequence stars of intermediate mass show the transition from the low density aggregates of T Tauri stars and the dense clusters around massive stars. Only the most massive stars (10-20 M_sun) are found to be associated with dense ( ~ 10(3 pc(-3)) ) stellar clusters. This is exactly the mass regime at which the conventional accretion scenario for isolated star formation faces theoretical problems. Thus our findings strongly supports the idea that the formation of high-mass stars is influenced by dynamical interaction in a young cluster environment
Plant Essential Oils as Biocides in Sustainable Strategies for the Conservation of Cultural Heritage
Full text linkBiodeterioration is a complex network of interactions between macro/micro-biological systems and organic/inorganic substrates involving physical and chemical alterations, strictly related to their metabolic activities. Concerning microbial deterioration, finding a correct approach to counteract this process is often difficult, requiring an understanding of the kind of alterations and the use of methods that respect artwork and human and environmental health. Specific conservative
and remedial methods are used for this aim. They comprise physical, mechanical, and chemical methods, as well as, frequently, synthetic chemical biocides, which have obvious limitations because of their toxicity to operators or because they contain polluting substances that persist in the natural environment. New and alternative research has strongly focused on strategies to replace the use of toxic methods with natural products that do not have undesired effects, as well as implementing safe, novel compounds. Several plants contain natural chemical compounds such as oils, phenols,
flavonoids, alkaloids, coumarins, tannins, etc., commonly used as drugs, bioactive molecules, and nutrients. Essential oils extracted from plants can be the correct way to prevent the biodeterioration of cultural heritage in a safe manner. This review aims to summarize the latest research on the use of natural essential oils in restoration procedures for cultural heritage considering them sustainable means with respect to the environment and human health
Biotechnology for microbial monitoring of indoor cultural heritage environments
Full text linkAn integrated approach for the characterization of bioaerosol was employed in different sites (that include hypogeal and semi-confined areas), characterized by great cultural/artistic interest besides peculiar architectural structures, thermo- hygrometric and lighting parameters. These typologies of indoor environments preserve several artworks like mural paintings, stone-works, paper or parchments that are susceptible of microbial colonization. The presence of fungal spores and low air change can induce both potentially effects to human health (users/operators) or biodegradation of historical-artistic manufacts. We perform bioaerosol sampling by a portable sampler (Sartorius MD8), equipped with gelatin filters and non-invasive sampling (Nylon membrane or sterile swab) is carried out on works of art surface. Microbial consortia is revealed and characterized by Optical, Scanning Electron and Confocal Laser Scanning Microscopy (OM, SEM, CLSM), in vitro culture and molecular analysis (PCR, sequencing, sequence analysis). The inter-disciplinary approach applied in this study, represents a valuable contribution for the proper planning of both direct and/or indirect biological growth control and for the conservative restoration procedure (1, 2).
This work was supported by Research Project It@cha - Italian Technologies for Advanced application in Cultural Heritage Assets, grant PON 01_00625 “Ricerca e Competitività” 2007-2013.
(1) Palla F. et al. (2006) Characterization of bacterial community in indoor environment. Heritage, Weathering and Conservation, 1: 361-365.
(2) Palla F. et al. (2010) Microscopy and molecular biology techniques for the study biocenosis diversity in semi-confined environments. Conservation Science in Cultural Heritage, 10: 185-194
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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