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Vitis vinifera L. cv. Agiorgitiko is one of the most popular indigenous wine grape varieties in Greece, cultivated almost exclusively in the Nemea Protected Designation of Origin (PDO) zone. Here, the microbiota of soil, grapes, and wine, during controlled (CF) and spontaneous (SF) fermentations of Agiorgitko cv. from three vineyards in the PDO Nemea zone were explored, using both classical microbiological analysis and metataxonomics to get evidence about the microbial terroir of the PDO Nemea zone. The classical microbiological analysis revealed higher total mesophilic counts in soil, while in both grapes and wine samples, yeasts prevailed. Lactic acid bacteria and acetic acid bacteria counts were lower in grapes compared to wine and soil. Metataxonomic analysis revealed that, regarding yeasts/fungi, genera Fusarium, Sarea, and Alternaria dominated in soil; Aureobasidium, Cladosporium, and Penicillium in grapes; Saccharomyces in wine during CF; and Hanseniaspora and Saccharomyces in wine during SF. Regarding bacteria, genera Skermanella, Acidobacterium, and Ohtaekwangia dominated in soil, Sphingomonas, Micrococcus, and Rubrobacter in grapes, while Tatumella, Alcanivorax, and Komagateibacter in wine during both CF and SF. Finally, the factors that significantly influence the microbiota of soil, grapes, and wine samples were assessed, and potential microbial biomarkers were identified for the first time in a Greek grape variety. [ABSTRACT FROM AUTHOR]

During antiquity, it is known that glass was produced in specialized primary workshops in Levant and Egypt, and this glass was melted and formed into objects in secondary workshops, and distributed in most cities and towns of the Roman Empire. Great efforts, although it is difficult, have been made to distinguish where it was produced. In this study, we perform chemical analysis on 48 glass samples (22 moils and 26 glass artefacts) dated to the 6th century CE from Vasileos Irakleiou Street, 45, Thessaloniki in northern Greece by using Scanning Electron Microscopy (SEM) with Energy–Dispersive X-ray microanalysis (EDX). All glasses were produced with natron as a flux and based on the sodium oxide content we divided them into two groups. Most of the glasses' chemical analysis indicates that they originated from Egypt, and can be categorized as HIMT and others as Roman Mn or Roman Mn-Sb. MnO is the main decolorizer, while in some samples MnO coexists with Sb2O3. Finally, recycling processes are evident in most of the samples. [ABSTRACT FROM AUTHOR]

The Qena basin (16,000 km2) represents one of the largest dry valleys located in the arid Eastern Desert of Egypt. Groundwater resources in this watershed are scarce due to limited recharge from annual precipitation. Hydrogeochemistry and environmentally stable isotopes were utilized to determine the main sources of recharge and geochemical processes affecting groundwater quality. The studied basin comprises three main groundwater aquifers: the Quaternary aquifer, the Post-Nubian aquifer (PNA) of the Paleocene-Eocene age, and the Nubian Sandstone aquifer (NSA) of the Lower Cretaceous age. Groundwater types vary from fresh to brackish groundwater. The groundwater salinity of the Quaternary aquifer ranges from 426 to 9975 mg/L with an average of 3191 mg/L, the PNA's groundwater salinity ranges from 1134 to 6969 mg/L with an average of 3760 mg/L, and the NSA's groundwater salinity ranges from 1663 to 1737 mg/L with an average of 1692 mg/L. The NSA's groundwater is relatively depleted of stable isotopes' signatures (ranges: δ18O from −9‰ to −4.81‰; δ2H from −71‰ to −33.22‰), whereas the Quaternary aquifer's groundwater is relatively enriched (ranges: δ18O from −5.51 to +4.70‰; δ2H from −40.87 to +37.10‰). Geochemical and isotopic investigations reveal that the NSA groundwater is a paleo-water recharged in a cooler climate. In contrast, the upstream Quaternary groundwater receives considerable recharge from recent meteoric water and upward leakage from the artesian NSA. The downstream Quaternary aquifer in the delta of the Qena basin is composed of original groundwater mixed with recharge from the River Nile. Isotopic analysis confirms that the PNA's groundwater recharge (ranges: δ18O from −5.90 to −0.10; δ2H −58.21 to −7.10‰) mainly originates from upward leakage from the NSA under the artesian condition and seepage from the upper unconfined Quaternary aquifer. NETPATH geochemical model results show that water–rock interaction, evaporation, and mixing are the main geochemical and physical processes controlling the groundwater quality. NSA groundwater has a significant regional extension and salinity suitable for use in expanding agricultural projects; it should be well managed for sustainable development. [ABSTRACT FROM AUTHOR]

Objectives: Isotopic analysis has been proven a valuable tool for reconstructing dietary habits in the ancient world. In this work we examine the evolution of Greek diet from the Neolithic period (6800–3000 BC) to modern times. Materials and Methods: We present isotopic analysis results for δ13C and δ15Ν of adult human bone collagen from ancient (Kaiadas in Sparta) and modern populations (Crete), while at the same time we review published results for δ13C and δ15Ν of adult human bone collagen from Neolithic to modern times of Greece. Results: The δ13C isotopic values evolve to more positive values, while they present a greater variability toward modern times. Furthermore, the δ15N values gradually increase over time. Discussion: We discuss the differences i) in human diet through time for the whole Greece and ii) individually for the island of Crete and we conclude that over time human diet becomes richer in high trophic level proteins such as marine sources with a larger variety of food sources. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the key quality characteristics of olive oil with a main focus on the biophenolic content, its beneficial effects on health and the contribution of various quality characteristics to its health claims, as well as its influence from various parameters. Samples from different traditional oil-producing regions of Greece were initially examined for the most important quality parameters, such as the percentage of free acidity, the number of peroxides and the spectrophotometric investigation in the ultraviolet. The samples were then tested for their biophenolic content, expressed in milligrams of tyrosol, and its derivatives per 20 g of olive oil using the analytical technique high-performance liquid chromatography (HPLC). Then, the biophenol contents of the analyzed samples were compared based on the presented intensities in terms of the variety and the area of cultivation, the altitude, the type of cultivation, the extraction system in the mill and the time interval from olive harvest to oiling. Finally, according to the results, the content of biophenols in olive oil and its health claims were found to be influenced by the various parameters with which they were compared. [ABSTRACT FROM AUTHOR]

In this article we present an isotopic analysis of human bone collagen (δ13Ccol, and δ15Ncol) and bone apatite (δ13C) for diet reconstruction, as well as δ18Oap of human bone apatite for climate reconstruction, using samples from Northern Greece. Radiocarbon dating analysis was conducted on three of the Agras samples and the results (from 1000 to 800 BC) correspond to the Early Iron Age. Isotopic values for δ13Ccol range from −20.5‰ to −16‰ and for δ15Ncol from 6‰ to 11.1‰—a strong indication of a C3-based diet, with contributions by C4 and freshwater fish elements. The results were compared to the ones from Roman Edessa, and Alexandreia (a contemporary city near Edessa), as well as to other Early Iron sites in Greece and wider Europe. In general, the results from Agras are in good agreement with the results from Northern Greece, with the exception of the Makriyalos site, and are quite close to those of Croatia's and Hungary's sites. Additionally, from the δ18Oap results we calculated the oxygen isotopic composition of consumed water for Agras (from −9.6‰ to −10.9‰) and for Roman Edessa (from −9.6‰ to −11.2‰) for the palaeoclimate and palaeomobility reconstruction. [ABSTRACT FROM AUTHOR]

Speleothems are useful in detecting past geoenvironmental events. Variations in trace element concentrations may constitute a diagnostic of volcanic eruptions, enabling both dating and environmental impact assessment. This work attempts to detect possible 'signatures' of past volcanic eruptions in speleothems from Zoodochos Pigi cave on Santorini. Higher-than-usual concentrations of elements and minerals (e.g. barium and monazite respectively) exotic to typical speleothem chemistry in a band within a flowstone retrieved from the cave were revealed through SEM-EDS and XRD analyses and thought to be of volcanic origin. By chance, charcoal trapped in the said speleothem band allowed dating to establish the timing of the volcanic event. The radiocarbon date pointed towards the historically documented Hiera eruption, the earliest of a series of volcanic eruptions that postdate the Minoan eruption. The Hiera eruption, although less violent than the Minoan eruption, signallised the recrudescence of intracaldera activity which culminated in the formation of Palea Kameni (197 BC) with palpable effects on the regional environment. The interpretation of the results presented here, i.e. geochemical analysis on speleothems and radiocarbon dating, are cross-correlated with the well-documented timeline of eruptions of Santorini and ancient literature. [ABSTRACT FROM AUTHOR]

The recently reported 'alarm photosynthesis' acts as a biochemical process that assimilates CO2 derived from the decomposition of calcium oxalate crystals. This study examined whether CaCO3 cystoliths could also serve as CO2 pools, fulfilling a similar role. Shoots of Parietaria judaica were subjected to carbon starvation, abscisic acid (ABA), or bicarbonate treatments, and the volume of cystoliths and the photochemical parameters of photosystem II (PSII) were determined. The size of cystoliths was reduced under carbon starvation or ABA treatments, whereas it was restored by xylem-provided bicarbonate. Under carbon starvation, ABA, or bicarbonate treatments, the photochemical efficiency of PSII was higher, while non-photochemical quenching, representing the safe dissipation of excess PSII energy due to lack of electron sinks, was lower in treated samples compared with controls. This observation suggests the involvement of ABA or other carbon starvation cues in the release of subsidiary CO2 for photosynthesis, inevitably from an internal source, which could be the cystoliths. Carbon remobilized from cystoliths can be photosynthetically assimilated, thus acting as a safety valve under stress. Together with alarm photosynthesis, these results show a tight link between leaf carbon deposits and photosynthesis. [ABSTRACT FROM AUTHOR]

The functional role(s) of plant calcium oxalate (CaOx) crystals are still poorly understood. Recently, it was shown that crystals function as dynamic carbon pools whose decomposition could provide CO2 to photosynthesis when stomata are closed (e.g. under drought conditions) and CO2 starvation conditions may be created within the mesophyll. This biochemical process, named as 'alarm photosynthesis', can become crucial for plant survival under adverse conditions. Here, we study crystal decomposition under controlled CO2 starvation conditions (either in the shoot or in the root) to obtain a better insight into the process of crystal formation and function. Hydroponically grown pigweed plants were kept in CO2‐free air and/or CO2‐free nutrient medium for 9 days. Crystal volume was monitored daily, and carbon stable isotope composition (δ13C) and Fourier transformation Raman spectra were obtained at the end of the experiment. A considerable reduction in the leaf crystal volume was observed in shoot‐CO2‐starved plants at the end of the experiment. The smallest crystals were isolated from the plants in which carbon was excluded from both the shoot and the root and contained potassium nitrate. Crystal δ13C of CO2‐starved plants was altered in a predicted way. Specifically, it depended on the average calculated isotope fractionation of all carbon fixation processes considered to be contributing in each experimental treatment. The results of the present study confirmed the correlation between CO2 starvation conditions and the CaOx crystal decomposition. Inorganic carbon fixed in the root may represent a major carbon source for CaOx formation. [ABSTRACT FROM AUTHOR]

Samples of mortars were collected from lime and hydraulic mortars affected by environmental degradation. A total of 63 samples were obtained from Hellenistic, Late Roman and Byzantine historic constructions located at Kavala, Drama and Makrygialos in North Greece. Samples were collected in sections from the surface up to 6 cm deep using a drill-core material. The first sample was collected from the external layer, while the internal samples were collected each 1 cm beeper from the previous, in order to monitor the moisture ingress. Isotopic data will make it possible to create an ideal Hellenistic and Byzantine mortar layer and to provide weathering gradients. The isotopic values comprise a range of δ13C and δ18O values from -17.1% to 1.2% and -25.9% -2%, respectively. The weathering process of Hellenistic and Byzantine are expressed, by the regression lines δ18Ocalcite matrix = 0.6 x δ13Ccalcite matrix =0.6 x δ13Ccalcite matrix -1.9 and δ18Ocalcite matrix = 0.6 x δ13Ccalcite matrix -2.0 for hydraulic and Lime mortars respectively. Pronounced isotopic shift to heavy or light δ13C and δ18O in the carbonate matrix was attributed to the primary source of CO2 (atmospheric versus biogenic) and H2O (evaporation of local primary water), in residual limestone and in secondary processes such as recrystallization of calcite with pore water and salts attack. Exogenic processes related to biological growth are responsible for further alterations of δ18O and δ13C in lime mortars. This study indicated that stable isotope analysis is an excellent tool to fingerprint the origin of carbonate, the environmental setting conditions of mortar, origin of CO2 and water during calcite formation and to determine the weathering depth and the potential secondary degradation mechanisms. [ABSTRACT FROM AUTHOR]

Wild boar and roe deer samples from an excavation in Dispilio, Greece, were subjected to collagen extraction protocols to reconstruct the paleoecological regime. Radiocarbon (14C) analysis suggested the Middle/Late Neolithic period and the database was updated with collagen samples. The 14C model concluded to a possible local deforestation effect in the settlement subbasin confirmed by sediment δ13C and δ15N values. Carbon isotope values in collagen samples concluded in C3 plant type. Both carbon and nitrogen isotopes indicated the differences in dietary habits and/or metabolic system between the two Late Neolithic I species. Roe deer samples were classified as purely herbivorous. δ15N values of wild boar collagen samples from Dispilio reflected a diet mainly characterized by terrestrial protein. Compared to literature data, wild boar samples from the Dispilio excavation concluded that the animals might have lived close to the settlement where their diet could be supplemented by a consistent animal protein fraction. Finally, it is concluded that rainfall is an important factor that affects plant, and consequently animal, δ15N values. Therefore, the rainfall regime should always be considered in paleodietary studies. [ABSTRACT FROM AUTHOR]

The present paper emphasizes the importance of measuring the oxygen isotopic and chemical compositions of ancient glass, in order to constrain some features such as age, raw materials, and production technologies and to identify the “fingerprint” of local productions. In this context, thirty-nine Roman and late Antique glass samples and eight chert samples from northern Greece were selected and analysed for their oxygen isotopic and chemical compositions. Results show that the majority of glass samples are produced using natron as flux and have δ18O values of about 15.5‰, plus or minus a few tenths of one per mil, suggesting that raw materials probably come from Levantine area. Four samples are heavily enriched in 18O, and their chemical composition clearly shows that they were made with soda plant ash as flux. Isotopic and chemical data of Greek chert samples support the hypothesis of local production of the above samples. About half of the glass samples have chemical compositions, which allow their age to be constrained to the late Antique period. For the remaining glass, similarities with literature compositional groups are reported and discussed. [ABSTRACT FROM AUTHOR]

Abstract: This paper investigates the stable isotopic composition from late Pleistocene–Holocene (~13 to ~10.5calka BP) shells of the land snail Helix figulina, from Franchthi Cave (Greece). It explores the palaeoclimatic and palaeoenvironmental implications of the isotope palaeoecology of archaeological shells at the time of human occupation of the cave. Modern shells from around the cave were also analysed and their isotopic signatures compared with those of the archaeological shells. The carbon isotope composition of modern shells depicts the consumption of C3 vegetation. Shell oxygen isotopic values are consistent with other Mediterranean snail shells from coastal areas. Combining empirical linear regression and an evaporative model, the δ18Os suggest that modern snails in the study area are active during periods of higher relative humidity and lower rainfall δ18O, probably at night. Late glacial and early Holocene δ18Os show lower values compared to modern ones. Early Holocene δ18Os values likely track enhanced moisture and isotopic changes in the precipitation source. By contrast, lower late glacial δ18O could reflect lower temperatures and δ18Op, compared to the present day. Shell carbon isotope values indicate the presence of C3 vegetation as main source of carbon to late glacial and early Holocene snails. [Copyright &y& Elsevier]

In recent years, isotopic analysis has been proven a valuable tool for the determination of the origin of various materials. In this article, we studied the 18O and 13C isotopic values of 210 olive oil samples that were originated from different regions in Greece in order to verify how these values are affected by the climate regime. We observed that the δ18O isotopic values range from 19.2 ‰ to 25.2 ‰ and the δ13C values range from −32.7 ‰ to −28.3 ‰. These differences between the olive oils' isotopic values depended on the regional temperature, the meteoric water, and the distance from the sea. Furthermore, we studied the 13C isotopic values of biophenolic extracts, and we observed that they have same capability to differentiate the geographic origin. Finally, we compared the isotopic values of Greek olive oils with samples from Italy, and we concluded that there is a great dependence of oxygen isotopes on the climatic characteristics of the different geographical areas. [ABSTRACT FROM AUTHOR]

In this paper, we study δ15N enrichment as an indicator not only of marine protein diet, but also of climate change. The slope of the variation of δ15N with precipitation was calculated equal to 0.38/100 mm of precipitation for Greek plants, 0.38/100 mm of precipitation for herbivores, and 0.32/100 mm of precipitation for the Greek human population (hair samples). As a case study, the slope was used to re-evaluate the published mean δ15N human bone collagen values from the Early Neolithic to Late Bronze Age for 22 archaeological sites. The results indicate that climate has a significant impact on the final δ15N values of plant and animal tissues. Furthermore, for the same sites, we investigated the intra-site diet patterns, while taking into account the environmental effect on the observed δ15N human bone collagen values. [ABSTRACT FROM AUTHOR]

We review the stable isotopic data of recovered Greek bones from the Early Neolithic to the Late Bronze period in order to examine dietary changes over time. As an isotopic baseline we use the published fauna data of the periods. The analysis revealed a diet that included a significant proportion of foods based on C3 plants, and the bulk of the animal protein must have been provided by terrestrial mammals with a small but detectable proportion of marine protein for coastal and island populations. A more significant contribution of marine protein is observed for Bronze Age populations while the enrichment in both C and N isotopes is connected, for some areas, to the introduction of millet during the Bronze Age, and to freshwater consumption. An extensive database of Greek food sources is presented and compared to the fauna from the prehistoric periods (Early Neolithic to Late Bronze Age) of the literature. We propose that this database can be used in palaeodiet reconstruction studies. [ABSTRACT FROM AUTHOR]

This paper reviews stable isotopic data concerning spring water in Greece in addition to new measurements (59); their spatial variations are investigated in order to provide basic information and identify the locally significant parameters that affect stable isotopic distributions. The area of interest was partitioned into eight sections according to geographical location and climatic characteristics. Local spring water lines (LSWLs) are more or less consistent throughout the country. High-resolution isoscape maps of spring freshwater (Cl− < 200 ppm; and T < 25 °C) for both δ18O and δ2H were generated, revealing several interesting features such as the effect of Pindos ridge, a strong climatic signal in southern Greece and indications of seawater intrusion in flat coastal areas. [ABSTRACT FROM AUTHOR]

Abstract: The water cycle is one of the key parameters that determine the climatic character of a region. Stable isotopes have long been established as a valuable tracer in the study of the origin, dynamics and interactions between the various components of the hydrologic cycle, both of the present and of the past. Even though significant efforts have been made, the spatial and temporal coverages of the available water isotope data are far from satisfactory. Statistical modeling and interpolation of existing measurements is a possible answer to this problem. This work is based on the experience gained by several recent studies in order to generate 0.5°×0.5° gridded monthly time series of δ 18Ο in the precipitation of the Eastern Mediterranean. The empirical model incorporates geographical and topographical data in order to capture the main modes of the spatial variability of the isotopic composition of precipitation, while the incorporation of meteorological data time series provides the necessary temporal variability. Overall, despite the rather coarse spatial resolution of the existing isotopic data, the applied methodology provides a satisfactory reproduction of the measurements. [Copyright &y& Elsevier]

Highlights: [•] Geo-structural and hydrogeological patterns: thermal waters discharge in a tectonic window. [•] Use of S isotopes to discriminate different evaporite sources, considering effects of BSR. [•] Use of the local approach instead of the regional approach to investigate the thermal site. [•] Use of geothermometric functions specifically calibrated for the thermal waters of interest. [•] Synthesis of geo-structural, hydrogeological and geochemical results in a conceptual model. [Copyright &y& Elsevier]

The recently reported 'alarm photosynthesis' acts as a biochemical process that assimilates CO2 derived from the decomposition of calcium oxalate crystals. This study examined whether CaCO3 cystoliths could also serve as CO2 pools, fulfilling a similar role. Shoots of Parietaria judaica were subjected to carbon starvation, abscisic acid (ABA), or bicarbonate treatments, and the volume of cystoliths and the photochemical parameters of photosystem II (PSII) were determined. The size of cystoliths was reduced under carbon starvation or ABA treatments, whereas it was restored by xylem-provided bicarbonate. Under carbon starvation, ABA, or bicarbonate treatments, the photochemical efficiency of PSII was higher, while non-photochemical quenching, representing the safe dissipation of excess PSII energy due to lack of electron sinks, was lower in treated samples compared with controls. This observation suggests the involvement of ABA or other carbon starvation cues in the release of subsidiary CO2 for photosynthesis, inevitably from an internal source, which could be the cystoliths. Carbon remobilized from cystoliths can be photosynthetically assimilated, thus acting as a safety valve under stress. Together with alarm photosynthesis, these results show a tight link between leaf carbon deposits and photosynthesis., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

The functional role(s) of plant calcium oxalate (CaOx) crystals are still poorly understood. Recently, it was shown that crystals function as dynamic carbon pools whose decomposition could provide CO 2 to photosynthesis when stomata are closed (e.g. under drought conditions) and CO 2 starvation conditions may be created within the mesophyll. This biochemical process, named as 'alarm photosynthesis', can become crucial for plant survival under adverse conditions. Here, we study crystal decomposition under controlled CO 2 starvation conditions (either in the shoot or in the root) to obtain a better insight into the process of crystal formation and function. Hydroponically grown pigweed plants were kept in CO 2 -free air and/or CO 2 -free nutrient medium for 9 days. Crystal volume was monitored daily, and carbon stable isotope composition (δ 13 C) and Fourier transformation Raman spectra were obtained at the end of the experiment. A considerable reduction in the leaf crystal volume was observed in shoot-CO 2 -starved plants at the end of the experiment. The smallest crystals were isolated from the plants in which carbon was excluded from both the shoot and the root and contained potassium nitrate. Crystal δ 13 C of CO 2 -starved plants was altered in a predicted way. Specifically, it depended on the average calculated isotope fractionation of all carbon fixation processes considered to be contributing in each experimental treatment. The results of the present study confirmed the correlation between CO 2 starvation conditions and the CaOx crystal decomposition. Inorganic carbon fixed in the root may represent a major carbon source for CaOx formation., (© 2018 Scandinavian Plant Physiology Society.)