https://www.um.edu.mt/library/oar/handle/123456789/314 Sat, 31 Oct 2026 00:19:15 GMT 2026-10-31T00:19:15Z https://www.um.edu.mt/library/oar/handle/123456789/150650 Title: Environmental monitoring of spores at a historic chapel Abstract: This study explores the airborne fungal spores, and pollen, present in and around the Church of the Annunciation, located in the uninhabited settlement of Ħal Millieri. Additionally, it assesses how environmental conditions may influence the presence of bioaerosols and the threat these may pose to the frescoes within the church. This church was chosen due to the unique paintings that adorn its walls, depicting twelve Catholic Saints. The paintings were executed in the fresco secco and buon affresco styles and date back to the fifteenth century. The frescoes are of particular importance to Malta’s cultural heritage as surviving medieval wall paintings are few and far between. A 24-hour pilot study was conducted to determine the ideal sampling duration and locations for the passive deposition method. Low bioaerosol counts highlighted the need for a longer sampling period. Therefore, three week-long sampling periods were conducted, with slides placed at twelve locations, both inside and outside the church. The passive sampling method was supplemented with active volumetric sampling using a portable Burkard volumetric air sampler. The samples were analysed via light microscope; the Burkard slides were converted to absolute and relative values of grains/m3. Results indicate that the building was largely effective at blocking the entry of bioaerosols, with only 3.55% of the total spores and 0.76% of the total pollen grains recorded indoors. The two sampling methods were complementary, with passive and active sampling better suited to detecting heavier and lighter particles, respectively. These findings highlight a conservation paradox: while maintaining indoor relative humidity above 75% prevented halite crystallization, it also created favourable conditions for fungal growth. Improving drought-proofing, alongside limiting visitor frequency and duration, could help reduce the ingress of bioaerosol. Description: B.Sc. (Hons)(Melit.) Thu, 01 Jan 2026 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/150650 2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/150571 Title: Invasiveness versus sustainability : supply chain perceptions of Opuntia ficus-indica in the Maltese food system Abstract: This research seeks to outline key contradictions in the agricultural uses, cultural values, economic opportunities, and ecological practices associated with the prickly pear cactus, Opuntia ficus-indica (OFI). Understanding contradictions in perspectives on invasive species like OFI aids in informing policy surrounding the environmental management of such species and contributes towards global research of invasive-food system integration, which is becoming increasingly important as climate change threatens traditional agricultural systems. This project analyzes necessary trade-offs associated with managing OFI in Malta through supply chain perceptions and valuation in primary markets, and consumer-side interviews in informal markets to capture perceptions and uses of the prickly pear cactus. Alongside a policy and literature review on historic and current uses, markets, and management practices, these data were analyzed through reflexive thematic analysis to create themes. Three major findings emerged from these analyses: contradictions between perceived nativeness and nonnative origins; nuanced views of plant classification impacted by cultural and food systems associations; and limited commercial development and institutional support despite OFI's climate resilience. A SWOT analysis was then used to evaluate potential futures for OFI. These findings presented three key pathways for OFI: increased investment, continuing current practices, and increased environmental regulation. These findings ultimately suggest that the role of OFI must be understood by the sum of its functions, as an environmental concern, agricultural resource, commercial product, and a cultural symbol. Any pathways for OFI are dependent on how stakeholders weigh trade-offs between these functions. Description: MSc. (EMS)(Melit.) Thu, 01 Jan 2026 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/150571 2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/150565 Title: Seasonal variability and multi-decadal trends of the mixed layer depth in the central Mediterranean Abstract: This study examined seasonal variability and multi-decadal trends of the Mixed Layer Depth (MLD) in the central Mediterranean. The primary objectives included addressing regional research gaps and evaluating three estimation methodologies to determine the most physically consistent approach for the region. The methods examined were the vertical temperature gradient, fixed temperature threshold, and density threshold (TEOS-10). MEDSEA_MULTIYEAR_PHY_006_004 physical reanalysis product from Copernicus Marine Service was used to provide daily temperature and salinity fields at a 1/24° (~4.5 km) horizontal resolution across 141 vertical levels. These reanalysis data were used to identify long-term trends and shifts in the MLD through daily estimates analyzed over 39 years, from 1 January 1987 to 1 January 2026. The findings indicate that the density threshold method (TEOS-10) was the most suitable framework. The most noteworthy result was a statistically significant spring shoaling trend of -0.87 m per decade that is indicative of seasonal stratification occurring earlier every decade. A possible association between MLD anomalies and to the presence of a gyre is identified. The results contribute to current regional knowledge of seasonal variability and multi-decadal trends, identify a statistically significant shoaling trend, and identify a possible association of MLD anomalies to the Malta-Sicily Gyre (MSG). Description: MSc. (EMS)(Melit.) Thu, 01 Jan 2026 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/150565 2026-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/150523 Title: Ryegrass hay versus whole crop silage : effects on milk C18:3 n-3 in Malta Authors: Attard, Everaldo; Spiteri, Jorgen; Pastorelli, Grazia Abstract: Cattle are fed a variety of diets around the globe, primarily depending on the producer and the location. Local whole crop silage and hay are the two major types of feed that farmers in Malta are accustomed to using. Ryegrass, an imported crop that is growing in popularity, is now being used by certain farmers. The goal of this study is to identify the benefits and drawbacks of each type of feed within a certain setting. For this investigation, two farms from which milk samples were obtained were taken into consideration. Farm A cows were fed on whole crop while Farm B relied on ryegrass. Although this was not statistically significant, quantitative analysis revealed that Farm B produced milk with a superior fatty acid profile. Such a study undoubtedly offers new avenues for farmers’ perspectives as well as for producers working with the herding of cattle. This study may be considered to be a pilot study for a more comprehensive investigation into the quality of locally produced fresh fodder and imported fodder that may contribute to the improvement of milk on local farms. Sun, 01 Jan 2023 00:00:00 GMT https://www.um.edu.mt/library/oar/handle/123456789/150523 2023-01-01T00:00:00Z