Search Results (37)

Pistacia lentiscus L. var. Chia is an endemic tree cultivated in the Southern part of Chios Greek Island. Chios mastiha, the aromatic resin secreted from this tree, has been used as traditional remedy since ancient times to cure many peptic system diseases and as a nutritional agent. Nowadays, Chios mastiha has been widely investigated for its biological activities and its chemical composition. A major part of Chios mastiha’s bioactive compounds are triterpenoids, which are proposed to interfere with glucocorticoid receptor (GR) signaling, acting as selective GR agonists. In this study a specific “neutral fraction” of Chios mastiha resin, a portion devoid of acidic triterpenoids, was investigated regarding its biological potential and chemical composition. The study aimed to determine if the neutral triterpenoids, the non-carboxylic ones, within this fraction drive Chios mastiha’s interference with GR signaling and whether it exhibits anti-inflammatory, apoptotic, and potential antilipidemic activities. The phytochemical characterization of this specific resin portion, applying ¹H NMR and HPLC-QTOF-MS/MS analysis, identified novel unidentified Chios mastiha’s phenolic components (apigenin, astragalin, diosmetin, flavidin, genistein), a complex mixture of fatty acids (palmitic, stearic, oleic), non-carboxylic triterpenoids (lupeol, β-amyrin, keto-oleanolic aldehyde), and a trace of terpenoids. Biological assessment of DEX-induced GR transcriptional activation revealed that neutral triterpenoid fractions only minimally contribute to GR transcriptional activation while positively regulating GR and its target, phosphoenolpyruvate carboxykinase (PEPCK), protein levels. Additionally, negative regulation of the peroxisome proliferator-activated receptor alpha (PPARα) protein levels as well as inhibition of the TNFα-induced NF-κΒ activity and reduction in the p65 subunit of NF-κΒ protein levels, were observed, indicating potential antilipidemic and anti-inflammatory Chios mastiha’s neutral fraction activities, which were attributed to its composition in triterpenoids, fatty acids, and novel phenolic compounds. Moreover, mitochondrial-dependent induction of apoptosis accompanied by reduction in cell viability was observed in lupeol, β-amyrin, and fatty acids-enriched fractions. The plethora of bioactive compounds associated with a variety of Chios mastiha’s neutral fraction render Chios mastiha a valuable food additive and nutritional agent. Full article

Background/Objectives: Fire is a dominant ecological force in Mediterranean ecosystems, shaping the adaptive traits of forest species such as Pinus brutia. Prescribed burning (also called controlled burning) is the intentional, carefully planned use of fire under specific environmental conditions to manage vegetation and reduce wildfire risk. While morphological and physiological fire adaptations are well-documented, emerging evidence highlights the role of epigenetic mechanisms—such as DNA methylation and histone modifications—in mediating stress responses. Methods: This study investigates genome-wide epigenetic changes in P. brutia following a prescribed burning experiment on Chios Island, Greece. Using methylation-sensitive amplified polymorphism (MSAP) analysis, we compared temporal shifts on epigenetic profiles before and after fire exposure extracting DNA from the same trees. Results: A significant increase in polymorphic epiloci, epigenetic diversity indices, and private epigenetic bands after prescribed burning was revealed, suggesting a stress-induced reprogramming of the epigenome. Concurrent measurements of midday needle water potential indicated an exploratory association between water stress and epigenetic shifts. Furthermore, Fireline Intensity (FI) correlated with epigenetic diversity index signaling an immediate response of the tree. Conclusions: These findings support the hypothesis that fire stress induces epigenetic responses in P. brutia, potentially enhancing resilience to future environmental challenges. Further research is required to address the level of heritability of these epigenetic changes in next generation and connect these indexes with adaptation and sustainability of forest ecosystems. Full article

Lethocerus patruelis (Stål, 1854), the sole European belostomatid, is an apex invertebrate predator in Mediterranean freshwater systems and a species known for its strong flight capacity and growing range expansion record. While its continental distribution in Greece is increasingly well documented, its presence across the Aegean islands has remained poorly characterized, with historical records scattered and often unpublished or fragmentary. Here, we present new, photographically verified records that substantially refine the species’ insular distribution and provide the first coordinated synthesis of its emerging archipelagic footprint. These include the first confirmed live individual from Samothraki and a newly documented specimen from Naxos, recovered beside a nearly desiccated summer stream indicating a very recent arrival. When integrated with additional verified observations from Sifnos, Ikaria, Chios, Euboea, Tilos, and Crete, as well as earlier published records, a coherent spatial pattern emerges. Rather than isolated vagrants, the records align along three longitudinal dispersal axes spanning the northern, central, and southern Aegean. These axes reflect plausible biological and anthropogenic pathways influenced by regional winds, maritime transport, and the distribution of natural and artificial freshwater habitats. Collectively, the evidence indicates that L. patruelis is undergoing a sustained, multi-vector archipelagic expansion, underscoring the importance of integrating citizen-science observations with targeted field documentation to monitor freshwater biodiversity across Mediterranean islands. Full article

Air pollution from ship operations can pose a significant challenge for coastal cities, particularly where ports are closely integrated into the urban fabric. This study examines the influence of ship docking on PM_2.5 concentrations in Chios, Greece, a medium size island city where the port directly borders densely populated neighbourhoods. Calibrated PurpleAir sensors were installed at urban and suburban sites to measure PM_2.5, with data analysed alongside ship call records and meteorological observations. An event-based concentration enhancement metric (%ΔC) was estimated to compare PM_2.5 during docking with the preceding 3 h background for 170 ship arrivals in February and August 2022. The results showed that under prevailing northerly winds in August, PM_2.5 at the downwind urban site increased on average by 5.0 µg m⁻³ (48%), whereas winter increments were smaller (6.1%) due to higher background variability. When both seasons and all wind directions were pooled, the urban site exhibited a mean enhancement of 1.7 µg m⁻³ (19%), while impacts at the suburban site remained minor (3%). Median-based uncertainty analysis confirmed robust enhancements under northerly winds only. Wind direction and wind speed were the primary controls on %ΔC, whereas ship engine power and time at berth had limited influence. The results suggest that ship-related PM_2.5 impacts are detectable but remain spatially and temporally limited in coastal urban environments, including medium-sized islands characterised by relatively low shipping activity. Full article

Climate change, a natural phenomenon driven by anthropogenic interventions, represents a global challenge that requires immediate and effective action. Significant alterations in atmospheric parameters and the occurrence of extreme climatic events have become increasingly evident. To evaluate extreme climate conditions and their variations within a specific region, climate data spanning at least five decades is essential. This study focuses on assessing the impacts of climate change on the island of Chios, with particular emphasis on its influence on the cultivation and harvesting of mastic gum, a unique product derived from the Pistacia lentiscus var. chia tree. Using ClimDex and analyzing 29 climate indices from 1960 to 2024, this paper evaluates historical and current climatic conditions. Key climate phenomena, such as the number of days with very high or low temperatures, extreme rainfall events, daily temperature variations, frost days, and days exceeding 25 °C—widely recognized indicators of climate change—are documented and correlated. Full article

Flash droughts are a significant natural hazard, characterized by rapid onset and potential to cause substantial economic and environmental impacts. This study utilizes ERA5 soil moisture data to identify and define historical flash drought (FD) events in the Northeastern Aegean islands (specifically Chios, Lemnos, Lesvos and Samos). Hourly soil moisture data, spanning from 1990 to the present, covering three soil layers (0–7 cm, 7–28 cm and 28–100 cm), were analyzed and mapped onto a 0.1° × 0.1° grid with a native resolution of approximately 9 km. Additionally, the Standardized Precipitation Evapotranspiration Index (SPEI) was applied to the island of Lesvos, using precipitation and average temperature data from the local meteorological stations. The number and characteristics of these events—including frequency, duration, decline rate, magnitude, intensity, recovery rate and recovery duration—were produced to construct a regional overview of FD risk across the Northeastern Aegean Islands. These results reveal a considerable variability in the spatial, seasonal and temporal distribution of past FD events. Furthermore, this study highlights the value of using satellite-derived soil moisture data for identifying FD events and demonstrates that analyzing this data with field temperature and precipitation measurements enables a more localized and accurate interpretation of past events. This approach facilitates the definition of FD “hotspot” areas, which, when combined with further investigation, can lead to the development of a predictive FD model. Full article

Mediterranean ecosystems are highly susceptible to wildfires, and shifts in fire patterns pose a threat to biodiversity, soil stability, and overall ecosystem health resilience. Implementing prescribed burning as a management strategy to lower wildfire risk has been proposed, but its ecological impacts in Greece are not well understood. This study examines the relationship between fireline intensity during prescribed burning and plant water potential, as well as its effects on soil properties and plant biodiversity on Chios Island, Greece. Field experiments were carried out in representative ecosystems, where we measured flame length to determine fireline intensity. In addition, we gathered soil samples before and after the prescribed burning and evaluated plant diversity. Measuring leaf water potential gave us a better understanding of how plants respond physiologically to different seasonal and site conditions. Our findings revealed that prescribed burning typically boosted plant diversity after the fire, with Fabaceae and Asteraceae playing a key role in regeneration. However, the soil responses differed from one site to another. Some sites saw a decline in organic carbon and nitrogen, while others showed an increase in exchangeable cations like calcium and magnesium, highlighting the importance of site-specific results. Studies on plant water potential revealed seasonal fluctuations in stress, underscoring the importance of accounting for seasonality in prescribed burn planning. Overall, prescribed burning has the potential to enhance biodiversity and ecosystem recovery, while also reducing fuel loads. These results highlight the importance of ongoing, site-specific monitoring for developing sustainable fire management strategies in Mediterranean ecosystems. Full article

Pistacia terebinthus L. which has been traditionally used in diet and medicine, remains underexplored in Greece, particularly regarding its chemical composition and antioxidant activity. The current study aims to comparatively evaluate the chemical profile of cold-pressed terebinth fruit oils, obtained from wild trees growing in the Greek Island of Chios (North East Aegean Sea), harvested during three years (2019, 2020 and 2021). The oils’ lipid profile was dominated by oleic acid (C18:1 cis-9) (42–45%) followed by palmitic acid (C16:0) (24–30%) and linoleic acid (C18:2 cis-9,12) (19–22%). Their phenolic acid content, expressed as anacardic acids—known for their bioactive properties—was quantified via q-¹H-NMR and found to be markedly high (1.91–2.98 mmol/kg oil). Total phenolic content (TPC) of the fruit extract showed interesting high value (185.92 ± 2.61 mg GAE/g) accompanied by strong antioxidant activity (DPPH, exhibiting > 80% inhibition at a concentration of 100 µg/mL) which was positively correlated with TPC. Additionally, the fruits demonstrated a rich nutritional profile, particularly in crude fibers (38.9%) and essential minerals (K, Mg, and Zn), along with low sodium content, suggesting notable dietary benefits. The cold-pressed oil exhibited high lipid content and low specific extinction coefficients (K₂₃₂, K₂₇₀), indicating minimal oxidation and confirming the oil’s freshness. These findings highlight the potential of P. terebinthus fruit oil as a high-value functional raw material with nutritional and antioxidant properties. Comparable to olive oil in lipid quality, Greek turpentine fruit and oil could play a promising role towards further applications in the food, cosmetic and pharmaceutical sectors. Full article

The decarbonization of short sea shipping is emerging as a critical priority for Mediterranean countries. This paper presents key findings from the ELECTRA-GR project, funded by the EEA Financial Mechanism (MIS 5202231), which aimed to evaluate the feasibility, technical readiness, and legislative requirements for the electrification of coastal ferry services in Greece. The study focused on two pilot routes—Salamis–Perama and Chios–Oinousses— representative of the high-frequency, short-distance ferry operations characteristic of the Greek archipelago. A comprehensive assessment was conducted combining technical fleet profiling, stakeholder consultations, legislative analysis, cost–benefit evaluations, and international benchmarking with Norway. For the base scenario of the high-traffic Salamis–Perama route, full electrification yields an annual reduction of approximately 900 tons of CO₂ compared to diesel operation and achieves a Net Present Value (NPV) of €1.6 million over a 15-year period. In contrast, the Chios–Oinousses route, characterized by lower traffic volume, achieves a reduction of 85 tons of CO₂ annually through hybrid conversion, but results in an NPV of €−1.69 million, underscoring the need for financial support mechanisms or targeted subsidies to ensure economic feasibility. The results indicate that electrification of short ferry routes in Greece is technically feasible and environmentally advantageous but faces significant challenges, including inadequate port infrastructure, regulatory gaps, and limited industrial readiness. The study proposes a structured roadmap toward electrification, emphasizing the modernization of shipyards, tailored policy instruments, and public–private cooperation. The findings contribute to the formulation of a scalable strategy for clean maritime transport in peripheral and island regions of Greece. Full article

The COVID-19 pandemic revealed long-standing vulnerabilities in island tourism economies such as Crete and Chios, including seasonality, overdependence on mass tourism, and limited innovation adoption. This study investigates how sustainable tourism, regional development, and innovation interconnect in these two cases. Drawing on structured questionnaires addressed to tourism stakeholders in Hersonissos (Crete) and Chios, we apply a comparative analysis through descriptive and inferential statistics. The findings reveal a common interest in diversifying tourism offerings through digital transformation and alternative tourism models. Hersonissos demonstrates higher engagement with innovation-led strategies, while Chios reflects a cautious but growing inclination toward eco-tourism and cultural tourism initiatives. The study employs a comparative cross-sectional design based on structured questionnaires addressed to 71 tourism stakeholders in Hersonissos and Chios. Data were collected through purposive sampling that was completed in July 2023. As a practical outcome, we propose the Regional Innovation Index in Tourism—a composite tool designed to assess innovation readiness at the local level. This index enables policymakers to evaluate the strategic capacity of tourism regions and supports the formulation of long-term, place-based development strategies aligned with EU policy goals and the transition to a green economy. Full article

Chios mastiha is the natural aromatic resin of Pistacia lentiscus L. var. Chia, Anacardiaceae, which is exclusively cultivated in the southern part of the Greek island of Chios. Chios mastiha (P. lenticonus/Chios mastiha) is well-known for its distinctive taste and aroma and has been known since ancient times due to its healing properties in gastrointestinal and inflammatory disorders and because of its anti-bacterial and anti-fungal activities. In this study, the chemical composition, applying LC-QTOF-MS/MS analysis, and the antioxidant activities of three different polarity P. lenticonus/Chios mastiha fractions, apolar, medium polar, and polar, were characterized in human neuroblastoma SH-SY5Y cells. Chemical analysis of the fractions unveiled new components of P. lenticonus/Chios mastiha, mainly fatty acids compounds, known for their antioxidant activity and regulatory effects on lipid metabolism. By applying the MTT assay and confocal microscopy analysis, we showed that P. lenticonus/Chios mastiha fractions, especially the apolar and medium polar fractions, enriched in triterpenes and fatty acids, caused suppression of the H₂O₂-induced reduction in cell viability, ROS production, and depolarization of the mitochondrial membrane potential, in SH-SY5Y cells. Moreover, Western blot analysis revealed that apolar fraction, enriched in fatty acids, induced expression of the PPARα, which is well-known for its antioxidant activities and its crucial role in lipid metabolism. Induction of PPARα, a GR target gene, was also accompanied by an increase in GR protein levels. Enhanced antioxidant activities of the apolar fraction may be correlated with its chemical composition, enriched in fatty acids and triterpenoids. Thus, our results indicate the neuroprotective actions of P. lenticonus/Chios mastiha fractions, highlighting their potential application as neuroprotective agents in neurodegenerative diseases. Full article

The Church of Panaghia Krena is a very important Byzantine monument situated in the island of Chios, well-known due to the high aesthetic value of the ceramic tile decoration on its facades and of its frescoes. The church suffered severe damage especially due to the 1881 devastating Chios earthquake and different interventions were implemented soon after (1884), consisting mainly of the reconstruction of collapsed areas and the addition of ties. Nevertheless, deterioration of old damages and appearance of new ones was observed. Thus, a restoration program was carried out between 2000 and 2007. This paper presents the basic characteristics of all types of historic materials examined, the main results of the in situ and laboratory experimental program carried out for the selection of the raw materials, and the design of optimum compositions of mortars and grouts to be used for the restoration works. The importance of in situ pilot applications is underlined, as well as of the production of site-specific aggregates for the repointing mortars by crushing a local rock, in order to succeed the adequate reddish color to match with the original mortars and bricks still preserved and achieve an aesthetic harmony with the color hue and texture of the original materials. Full article

Electricity load forecasting is a crucial undertaking within all the deregulated markets globally. Among the research challenges on a global scale, the investigation of deep transfer learning (DTL) in the field of electricity load forecasting represents a fundamental effort that can inform artificial intelligence applications in general. In this paper, a comprehensive study is reported regarding day-ahead electricity load forecasting. For this purpose, three sequence-to-sequence (Seq2seq) deep learning (DL) models are used, namely the multilayer perceptron (MLP), the convolutional neural network (CNN) and the ensemble learning model (ELM), which consists of the weighted combination of the outputs of MLP and CNN models. Also, the study focuses on the development of different forecasting strategies based on DTL, emphasizing the way the datasets are trained and fine-tuned for higher forecasting accuracy. In order to implement the forecasting strategies using deep learning models, load datasets from three Greek islands, Rhodes, Lesvos, and Chios, are used. The main purpose is to apply DTL for day-ahead predictions (1–24 h) for each month of the year for the Chios dataset after training and fine-tuning the models using the datasets of the three islands in various combinations. Four DTL strategies are illustrated. In the first strategy (DTL Case 1), each of the three DL models is trained using only the Lesvos dataset, while fine-tuning is performed on the dataset of Chios island, in order to create day-ahead predictions for the Chios load. In the second strategy (DTL Case 2), data from both Lesvos and Rhodes concurrently are used for the DL model training period, and fine-tuning is performed on the data from Chios. The third DTL strategy (DTL Case 3) involves the training of the DL models using the Lesvos dataset, and the testing period is performed directly on the Chios dataset without fine-tuning. The fourth strategy is a multi-task deep learning (MTDL) approach, which has been extensively studied in recent years. In MTDL, the three DL models are trained simultaneously on all three datasets and the final predictions are made on the unknown part of the dataset of Chios. The results obtained demonstrate that DTL can be applied with high efficiency for day-ahead load forecasting. Specifically, DTL Case 1 and 2 outperformed MTDL in terms of load prediction accuracy. Regarding the DL models, all three exhibit very high prediction accuracy, especially in the two cases with fine-tuning. The ELM excels compared to the single models. More specifically, for conducting day-ahead predictions, it is concluded that the MLP model presents the best monthly forecasts with MAPE values of 6.24% and 6.01% for the first two cases, the CNN model presents the best monthly forecasts with MAPE values of 5.57% and 5.60%, respectively, and the ELM model achieves the best monthly forecasts with MAPE values of 5.29% and 5.31%, respectively, indicating the very high accuracy it can achieve. Full article

The evolution and drivers of dense water formation (DWF) in the North–Central Aegean Sea (NCAeg) during winter 2021–2022 are studied using observations from two Argo floats and the output of an operational data-assimilating model. Dense water with ${\sigma }_{\theta }>29.1 {\mathrm{kg}\mathrm{m}}^{-3}$ was produced over most of the NCAeg, except for the northeastern part covered by Black Sea water (BSW), where the maximum surface density was $<29 {\mathrm{kg}\mathrm{m}}^{-3}$. The highest density waters were produced over the central and southern parts of the Lemnos Plateau and in the shallow coastal areas between Chios Island and the Edremit Gulf. Atmospherically driven transformation to the east of Lesvos Island resulted in the production of waters with anomalously high density and salinity, which flowed inside Skiros Basin, thus partly explaining its historically higher density and salinity compared to the rest of the NCAeg subbasins. The Skiros and Athos Basins were ventilated down to ${\sigma }_{\theta }$∼$29.35 {\mathrm{kg}\mathrm{m}}^{-3}$ horizons. The $29.1 {\mathrm{kg}\mathrm{m}}^{-3}$ isopycnal rose by ∼$200 \mathrm{m}$, and the $29.25 {\mathrm{kg}\mathrm{m}}^{-3}$ isopycnal overflowed above the ∼$400 \mathrm{m}$ sill depth filling the southern depressions of the NCAeg. Combining data from Argo floats, vessel casts, gliders, and a fixed-point observatory, the dense water produced in the NCAeg was observed spreading in the deep layer of the Central Cretan Sea for at least one and a half years after the formation. The cyclonic circulation of the newly formed water in the NCAeg has been observed directly for the first time using deep-drifting floats. The Eastern Mediterranean warming and salinification signal has propagated below the NCAeg sill depth. The winter average buoyancy loss was comparable to that of the peak of the Eastern Mediterranean transient (EMT) and other known years of DWF in the NCAeg; however, the high temperature of the upper layers due to long-term warming prevented the widespread formation of denser water. Full article

In the Mediterranean, one of the most fire-prone regions in the world, wildfires are considered a key factor in vegetation distribution, structure, and function. Severe or frequent fires can lead to homogenized plant communities and habitat fragmentation with significant consequences for the ecosystem and plant-dependent animals such as pollinators. Herein, we present the results of a 10-year post-fire study (2013–2022) conducted on Chios Island, Greece. We explored the effects of a large-scale fire on beta diversity patterns of the flowering insect-pollinated plant communities and its turnover and nestedness components in both burned and unburned sites. In addition, we investigated whether the recorded differences in the burned and unburned plant communities were a result of species gains or losses in the post-fire years. Burned communities display higher post-fire beta diversity compared to the unburned ones, due to higher species turnover across all years of reference. Species turnover was highest overall in the burned sites during the second post-fire year and decreased a decade later. In conclusion, Mediterranean flowering insect-pollinated plant communities are rather fire-resilient, implying positive impacts on pollinator diversity and plant-pollinator interactions during regeneration after a wildfire. Full article