2,532 research outputs found
Coastal problems : geomorphology, ecology and society at coast/ Viles
No full textx, 350 hal.: ill, tab.; 25 cm
Ecosustainable and phytobased alternative methods for the conservation of biodeteriorated stone materials
Get PDFIl presente lavoro di tesi propone di sviluppare un metodo finalizzato al trattamento di materiali lapidei biocolonizzati, tramite l’impiego di sostanze chimiche di origine naturale (i.e. fitochimici), caratterizzati da un basso impatto ambientale, una bassa tossicità per l’uomo e che non compromettano lo stato conservativo dei beni culturali.
In questa prospettiva, sono state sfruttate le già note proprietà biocide di tre Oli Essenziali (EOs) già largamente studiati e impiegati in diversi ambiti, tra cui quello della conservazione dei beni culturali. Tali sostanze sono ottenute a partire da piante molto comuni della flora mediterranea, ed in particolare si tratta degli oli di Origanum vulgare, Thymus vulgaris e Clinopodium nepeta. Ogni olio essenziale ha una composizione chimica molto eterogenea, sebbene siano sempre presenti uno o due componenti chimici maggioritari, anche definiti Principi Attivi (APs), che ne definiscono il chemiotipo e sembrerebbero condizionarne l’azione biocida, sebbene non sia ancora stato sistematicamente dimostrato. In virtù di quanto detto, l’effetto biocida dei tre oli essenziali è stato confrontato con quello dei loro rispettivi principi attivi ovvero: carvacrolo per O. vulgare, timolo per T. vulgaris e pulegone per C. nepeta.
Per valutarne un possibile incremento dell’azione biocida, ogni olio è stato applicato singolarmente e in combinazione con gli altri due, in modo da creare diverse miscele contenenti rispettivamente, uno, due e tre composti, e lo stesso è stato fatto per i principi attivi. L’applicazione sulle superfici lapidee biocolonizzate ha previsto l’incapsulamento delle sostanze attive all’interno di una matrice idrogel (HG) di nuova formulazione, composta dalla miscela di sostanze polimeriche e tensioattivi, i cui più grandi vantaggi sono legati all’atossicità nella composizione chimica e alla capacità di formare un film omogeneo, pelabile, facile da rimuovere dalle superfici una volta asciutto. I composti sono stati testati su diversi biofilm presenti su substrati lapidei in granito e travertino. In particolare, le sperimentazioni hanno previsto l’applicazione su campioni di granito (in laboratorio) e su due superfici murarie, una in granito e una in travertino, esposte a diverse condizioni ambientali. Per la valutazione dell’azione biocida e pulente dei composti fitochimici, sono state effettuate misure non invasive di colore e di fluorescenza che potranno essere replicate anche sui beni culturali. Il sistema ottenuto dalla combinazione dell’idrogel e dei fitochimici (phyto-HG) ha mostrato buoni risultati per quanto riguarda l’azione pulente e biocida nei confronti di differenti biofilm, anche rispetto a quelle dimostrate da un sistema classicamente utilizzato per la pulitura meccanica dei beni culturali (spazzolatura) e di un comune biocida (Preventol® RI80).
Le prove sperimentali hanno messo in evidenza l’efficacia dei principi attivi i quali, possono essere considerati, nella maggior parte dei casi, più efficienti rispetto ai corrispondenti oli essenziali. Questo risultato è molto incoraggiante per le future sperimentazioni riguardanti lo sviluppo del metodo, che potrebbe prevedere l’impiego dei soli principi attivi per la realizzazione delle formulazioni biocide, con i notevoli vantaggi legati ai minori costi di produzione e alla possibilità di ridurre i limiti legati all’impossibilità di controllare le composizioni chimiche degli estratti naturali.
L’azione ottenuta dalla combinazione di più sostanze necessita ulteriori approfondimenti, in quanto sembrerebbe che la loro azione sia condizionata dalla sinergia che si ottiene da più sostanze nei confronti di specifici microorganismi presenti.
Il monitoraggio a medio e a breve termine effettuato sui campioni sperimentali ha evidenziato un’azione prolungata delle sostanze nel tempo. Sebbene questo non possa essere considerato sempre vantaggioso, in quanto ci si potrebbero aspettare delle reazioni secondarie che potrebbero verificarsi tra i residui e la matrice lapidea, è importante comunque sottolineare i vantaggi legati all’inibizione a lungo termine nei confronti di una possibile ricolonizzazione della superficie. Per queste ragioni, risulta importante analizzare più approfonditamente la stabilità dei fitochimici nel tempo, tramite l’osservazione di possibili modifiche delle proprietà chimiche ed estetiche dei materiali.The present PhD thesis aims to develop a valid strategy for the treatment of the biocolonization of stone materials, by employing natural chemical substances (i.e. phytochemicals) harmless towards ecosystems, human health, and cultural heritage materials. To achieve this goal, the well know biological properties of the Essential Oils (EOs) have been exploited, by employing three of these plant extracts that have already demonstrated inhibitory effects towards different microorganisms. These oils are obtained from Mediterranean plants of the Lamiaceae family, in particular: Origanum vulgare, Thymus vulgaris and Clinopodium nepeta. Each EO is characterized by the presence of one or two mayor chemical components, also defined Active Principles (APs). It seems that the biocidal action of each EO is established by the presence of specific APs, although this was not systematically proven. To demonstrate what has just been said, in this study, the effect of the EOs has been compared to the one of the respective APs, which are carvacrol for O. vulgare, thymol for T. vulgaris and pulegone for C. nepeta. Each EO has been applied alone and combined with the two others, in mixtures containing two and three EOs. The same process occurred with the APs. This was done to assess a possible empowerment of the biocidal action when more substances are combined. For their application on biodegraded stone surfaces, the phytochemicals were incorporated inside an innovative hydrogel (HG) matrix based on a mixture of polymeric substances and surfactants; whose main advantage is linked to its ability of forming a peelable layer when applied on surfaces. The compounds were tested on biofilms, colonizing granite and travertine surfaces. The experimentations were performed on granite samples and on two biocolonized walls, one in granite and the other in travertine. The biocidal and cleaning properties of the systems composed by the phytochemical substances and the hydrogel have been assessed through non-invasive colorimetric and fluorescence measurements. The phyto-HG systems demonstrated good cleaning and large spectrum biocidal properties against different biofilms, also compared to the ones of a commonly employed mechanical cleaning tool (brushing) and a common biocide (Preventol ® RI80).
The APs also showed their broad-spectrum biocidal action, which can be considered, in many cases, higher than the one of the respective EOs. This is an encouraging result, in sight of possible future developments of the method, that will provide the employment of the only APs for the creation of the formulations, with notable advantages linked to the reduction of the production costs and the possibility of reducing the limits linked to the impossibility of controlling the chemical composition of the natural extracts (i.e. the EOs).
The action of the combined substances compared to biofilms needs to be further analysed, because it seems that their action is strongly linked to the synergism occurring between two substances and the specific microorganisms present.
The short-term and medium-term monitoring carried out on the experimental samples evidenced a prolonged action of the substances in time. Even though this is not always encouraged, since possible secondary reactions may occur between the chemical residuals and the mineralogical matrix, it is important to stress the advantage related to the long-term inhibition towards a secondary biological growth on the surfaces. For these reasons, it will be important to further analyse the stability of the substances in time, by observing possible modifications in the properties of the stones during the time
What controls algal greening of sandstone heritage? An experimental approach
Get PDFRecent observations have shown that many sandstone buildings, including important components of the UK’s cultural heritage, are becoming covered with green algal growths. This is likely to result from recent changes in air quality and the impacts of a changing climate. The northern regions of the UK in particular have an abundance of sandstone heritage and, given the likelihood of warmer, wetter winters here, algal growth on vulnerable monuments is likely to become a primary conservation concern over the next 50 years. Observations of sandstone monuments in the northern regions of the UK, in particular in Belfast (Northern Ireland), Sheffield and Edinburgh have highlighted that algal greening is notably patchy. This is likely due to the array of factors which affect the bioreceptivity of host substrates such as sandstone. The bioreceptivity of a substrate (its ability to become colonised by microbes such as green algae) is dependent on inherent, external and architectural factors. The role of these factors and the interrelationships between them requires further study.
This thesis aims to investigate the inherent, external and architectural factors which encourage colonisation of sandstone by green algae through an integrated programme of laboratory and field experimentation. The primary objectives of this study are: to develop improved laboratory experimental methods to control and monitor algal growth, to investigate the role of external, inherent and architectural factors and to explore the fundamental role of moisture in the development of algal greening.
In order to address these objectives, laboratory and field experiments have been linked within an integrated overall methodology. Short-term laboratory experiments have investigated the bioreceptivity of four British sandstones (Peak Moor, Dungannon, St Bees and ‘baluster stone’) to single and mixed green algal treatment with Stichococcus bacillaris, Chlorella vulgaris and Desmococcus olivaceus, under controlled conditions. Two field experiments have also been conducted. The first exposed unweathered blocks of Dungannon sandstone in the wet environment of Derrygonnelly, Northern Ireland for 30 months. The second exposed reclaimed sandstone balusters in a shaded and exposed site in central Oxford for 12 months. The laboratory and field experiments presented utlilise a range of simple and accessible methods to monitor biofilm development (for example novel methods to map biomass) and changes in substrate condition (such as monitoring surface moisture movements with weight change and hand-held moisture meters, and using light microscopy to help visualise the impact of green algal biofilms).
The results presented in this thesis confirm that moisture plays a fundamental role in the development of green algal biofilms. In laboratory experiments, colonisation often occurred within a consistent moisture zone and preferential greening in field experiments was observed in areas of frequent moisture movement. External factors have been shown to have a strong influence, in laboratory experiments where marine salts were applied, these were found to delay colonisation by around seven days. Furthermore, salts resulted in inhomogeneous patterns of colonisation, similar to those observed in scoping studies conducted in Sheffield. Laboratory experiments have also demonstrated that inherent substrate factors such as high porosity and presence of certain minerals (such as clay laminations in Dungannon) can increase the primary bioreceptivity of sandstone surfaces.
Field experiments have demonstrated that architectural factors such as aspect and geometry can increase the bioreceptivity of exposed samples. In particular, preferential greening was observed on the dynamically wetted south west facing blocks in Derrygonnelly and on exposed compared with shaded balusters in Oxford. Greening was also concentrated in areas of rainwater flows and stores.
Investigation of the role of external, inherent and architectural factors in the development of algal greening as provided by this project, supplies useful information for those managing our sandstone cultural heritage. This will enable more informed decisions to be made over appropriate management and conservation strategies for the future
The Times, They Are Changing
No full textIn 2015, Rutgers became only the second accredited law school in the United States to select the open-source ILS, Koha. The merger of two unique catalogs at Rutgers Law School has presented unique challenges with respect to migration mapping, data recall for large records, and relevancy ranking, all of which affect search results and usability of the OPAC. System migrations always result in some data being lost or incorrectly transferred. The hope is to minimize just how much data is compromised while fixing errors that might not have come to light but for the migration.Peer reviewe
Heather McHugh, 4th Annual ODU Literary Festival
No full textThe author of Dangers, published in 1978 in Houghton Mifflin\u27s New Poetry Series, and A World of Difference, also a Houghton Mifflin publication (1981), Heather McHugh is a rare poet, known for her formal elegance, her piercing wit, and her supple use of rhyme and rhythm. The Denver Quarterly remarked on her interest in seeing doubly and double-talking and praised her passionate intelligence and affection for the tongue\u27s intimate intricacies. McHugh\u27s Thursday evening reading will conclude the 1981 Literary Festival. McHugh grew up in Williamsburg and now teaches at the State University of New York at Binghamton. She is a member of the board of directors of the Associated Writing Programs
Ep. #121 - Heather Paxson
No full textThis recording and transcript form part of a collection of podcasts conducted by the Cultures of Energy at Rice University. Cultures of Energy brings writers, artists and scholars together to talk, think and feel their way into the Anthropocene. We cover serious issues like climate change, species extinction and energy transition. But we also try to confront seemingly huge and insurmountable problems with insight, creativity and laughter.Dominic and Cymene plug Cultures of Energy 7—this year’s energy humanities symposium at Rice which begins today, details at culturesofenergy.org—and then they turn to cheese, why it’s funny, how it can be applied to cats, “cheddaring,” and much more. Is there an anthropologist who knows more about cheese than anyone? Yes of course there is, it’s MIT’s Heather Paxson, author of the award-winning The Life of Cheese: Crafting Food and Value in America (U California Press, 2012). She joins us (14:59) to talk about her research on the microbiopolitics of food and naturally we begin with what’s in her fridge. Heather tells us about her investigation of artisanal cheesemaking and what it tells us about the shift from Pasteurian to Post-Pasteurian regimes of microbiopower. We hear about goat ladies as revolutionaries, the truth about vegan cheese, and debate whether artisanal foodmaking is an elite project. Heather discusses the search for moral meaning in everyday life as a throughline in her work and we turn to her latest research on food safety inspections, the porosity of food borders and the synecdochic reasoning of the state when it comes to managing food flows. We close by discussing the impact of feminist analytics of labor in her research. What is “beef candy China”? Listen on and you might just find out
HERStory Makers 2023: Heather Mcclelland
No full textHeather Mcclelland is a chartered psychologist and researcher at the University of Glasgow studying mental health. She took part in HERStory Makers 2023.What is HERStory Makers?HERStory Makers is a social media competition for female-identifying early career researchers to share their research, their career journeys, and to inspire the next generation. Winners are selected by public vote. HERStory Makers is also part of EXPLORATHON, Scotland's contribution to European Researchers' Night.In 2022-23, EXPLORATHON was supported by the Engineering & Physical Sciences Research Council [grant number EP/X020762/1].Author contributions to contentHeather Mcclelland conceived, planned, and recorded the video content. Kirsty Ross edited the video content to insert HERStory Maker credits, add subtitles, and ensured the video length was below Twitter/X limit of 2 mins and 20 secs.</p
Creating and Scaling Innovative School Models Through Strategic Partnerships
Get PDF· The Texas High School Project (THSP) was created in 2003 as a public-private alliance to support education reform across the state.
· This article focuses on the pivotal role of philanthropy within the THSP alliance to create early college high schools (ECHS).
· The model has been scaled at different levels to produce direct, affordable pathways for students to both attend college and attain skilled careers.
· The ECHS schools have higher test scores, greater credits earned, and reduced dropouts rates compared to traditional schools.
· Foundations with a track record for supporting successful work can increase the overall commitment to joint projects and attract additional members and support to an alliance.
· Lessons for successful partnerships include investing in time together, managing the partnership through one organization, and using data for decision-making
Institutional Racism and the Dynamics of Privilege in Public Health
No full textInstitutional racism, a pattern of differential access to material resources and power determined by race, advantages one sector of the population while disadvantaging another. Such racism is not only about conspicuous acts of violence but can be carried in the hold of mono-cultural perspectives. Overt state violation of principles contributes to the backdrop against which much less overt yet insidious violations occur. New Zealand health policy is one such mono-cultural domain. It is dominated by western bio-medical discourses that preclude and under-value Māori, the indigenous peoples of this land, in the conceptualisation, structure, content, and processes of health policies, despite Te Tiriti o Waitangi guarantees to protect Māori interests.
Since the 1980s, the Department of Health has committed to honouring the Treaty of Waitangi as the founding document of Māori-settler relationships and governance arrangements. Subsequent Waitangi Tribunal reports, produced by an independent Commission of Inquiry have documented the often-illegal actions of successive governments advancing the interests of Pākehā at the expense of Māori. Institutional controls have not prevented inequities between Māori and non-Māori across a plethora of social and economic indicators.
Activist scholars work to expose and transform perceived inequities. My research interest lies in how Crown Ministers and officials within the public health sector practice institutional racism and privilege and how it can be transformed. Through dialogue with Māori working within the health sector, fuelled by critical analysis and strategic advice from a research whānau (family) of Māori health leaders and a Pākehā Tiriti worker, and embracing the traditions of feminist and critical race theory I provide evidence of racism that can invoke strong emotional reactions. More disturbing is its normalisation to nigh imperceptibility within ones personal and professional life. The exposure of racism as a socially created phenomenon is a strength of the research presented here.
My action orientation is my ethical response. Honouring Te Tiriti o Waitangi is a pathway to transforming racism. Such change is likely to be resisted by the Pākehā majority. This anticipated resistance is not a credible reason to weaken responsibility for such necessary change. Transforming institutional racism needs to be driven by senior managers, professional bodies, unions, and by communities. Policies, practices and leadership that enable institutional racism need to be systematically eliminated from the health sector. Crown officials must be supported to strengthen their professional accountabilities and to embrace ethical bicultural practice. Greater transparency could enable more effective monitoring of Crown behaviour and support transformed practice
Why Look at Animals in Landscapes?
No full textThis book was published on the occasion of the two-person exhibition Reflexive Animals with work by Heather Passmore and Carrie Walker. The exhibition was held at SFU Gallery from September 8 to October 20, 2012. It includes written contributions by artist Julie Andreyev, poet Peter Culley and Bill Jeffries.final article publishe
- …
