Point Pattern Analysis (PPA) as a tool for reproducible archaeological site distribution analyses and location processes in early iron age south-west Germany.

Point Pattern Analysis (PPA) has gained momentum in archaeological research, particularly in site distribution pattern recognition compared to supra-regional environmental variables. While PPA is now a statistically well-established method, most of the data necessary for the analyses are not freely accessible, complicating reproducibility and transparency. In this article, we present a fully reproducible methodical framework to PPA using an open access database of archaeological sites located in south-west Germany and open source explanatory covariates to understand site location processes and patterning. The workflow and research question are tailored to a regional case study, but the code underlying the analysis is provided as an R Markdown file and can be adjusted and manipulated to fit any archaeological database across the globe. The Early Iron Age north of the Alps and particularly in south-west Germany is marked by numerous social and cultural changes that reflect the use and inhabitation of the landscape. In this work we show that the use of quantitative methods in the study of site distribution processes is essential for a more complete understanding of archaeological and environmental dynamics. Furthermore, the use of a completely transparent and easily adaptable approach can fuel the understanding of large-scale site location preferences and catchment compositions in archaeological, geographical and ecological research.

A dataset to model Levantine landcover and land-use change connected to climate change, the Arab Spring and COVID-19.

The Levant is highly vulnerable to climate change and experiences prolonged heat waves that have led to societal crises and population displacement. In addition, the region has been impacted by further socio-political turmoil at least since 2010, including the Syrian civil war and currently the escalation of the so-called Israeli-Palestinian Conflict, which strained neighbouring countries like Jordan due to the influx of Syrian refugees and increases population vulnerability to governmental decision-making. Jordan, in particular, has seen rapid population growth and significant changes in land-use and infrastructure, leading to over-exploitation of the landscape through irrigation and unregulated construction activity. This article uses climate data, satellite imagery, and land cover information in a multicomponent trend analysis to illustrate the substantial increase in construction activity and to highlight the intricate relationship between climate change predictions and current socio-political development in the Levant. The analyses were performed using annual and seasonal composites of MODIS (Moderate Resolution Imaging Spectroradiometer) NDVI (Normalized Difference Vegetation Index) datasets with a spatial resolution of 250 m compared to climate indices of the GLDAS (Global Land Data Assimilation System) Noah Land Surface Model L4 dataset for the period 2001-2023. Surface reflectance and climatic parameters were then evaluated on the basis of socio-cultural factors, such as population dynamics, governmental decision-making, water withdrawal regulations, and built-up change as a result of large-scale migration processes. All analyses were conducted using R-software and can be reproduced and replicated using the code and the data provided in this article and the repository.

Rapid Spin Depolarization in the Layered 2D Ruddlesden-Popper Perovskite (BA)(MA)PbI.

We report temperature-dependent spectroscopy on the layered (n = 4) two-dimensional (2D) Ruddlesden-Popper perovskite (BA)(MA)PbI. Helicity-resolved steady-state photoluminescence (PL) reveals no optical degree of polarization. Time-resolved PL shows a photocarrier lifetime on the order of nanoseconds. From simultaneously recorded time-resolved differential reflectivity (TRΔR) and time-resolved Kerr ellipticity (TRKE), a photocarrier lifetime of a few nanoseconds and a spin relaxation time on the order of picoseconds was found. This stark contrast in lifetimes clearly explains the lack of spin polarization in steady-state PL. While we observe clear temperature-dependent effects on the PL dynamics that can be related to structural dynamics, spin relaxation is nearly T-independent. Our results highlight that spin relaxation in 2D (BA)(MA)PbI occurs at time scales faster than the exciton recombination time, which poses a bottleneck for applications aiming to utilize this degree of freedom.

Bioarchaeological analyses reveal long-lasting continuity at the periphery of the Late Antique Roman Empire.

The Basel-Waisenhaus burial community (Switzerland) has been traditionally interpreted as immigrated Alamans because of the location and dating of the burial ground - despite the typical late Roman funeral practices. To evaluate this hypothesis, multi-isotope and aDNA analyses were conducted on the eleven individuals buried there. The results show that the burial ground was occupied around AD 400 by people belonging largely to one family, whereas isotope and genetic records most probably point toward a regionally organized and indigenous, instead of an immigrated, community. This strengthens the recently advanced assumption that the withdrawal of the Upper Germanic-Rhaetian limes after the "Crisis of the Third Century AD" was not necessarily related to a replacement of the local population by immigrated Alamannic peoples, suggesting a long-lasting continuity of occupation at the Roman periphery at the Upper and High Rhine region.

Scales of transformations-Modelling settlement and land-use dynamics in late antique and early medieval Basel, Switzerland.

Multicomponent environmental models have increasingly found their way into archaeological research. Mostly, these models aim to understand human patterns as a result of past climatic and environmental conditions over long-term periods. However, major limitations are the low spatial and temporal resolution of the environmental data, and hence the rather static model output. Particular challenges are thus the number of chosen variables, the comprehensiveness of the explanatory parameters, and the integration of socio-cultural decision-making into the model. Here, we present a novel approach to generate annually resolved landcover variability using a broad variety of climatic, geological, hydrological, topographical, and dendrochronological data composites (Palmer Drought Severity Index (PDSI)). We analyze land-use and settlement capacity and vulnerability to estimate the socio-cultural transformation processes at Basel (Switzerland) during the Late Antiquity and the Early Middle Ages. Our results highlight the potential of the PDSI to predict local river run-off behavior from catchment analyses. The model enables to trace landcover as well as socio-cultural response to climatic variability and subsequent adaptation to trends in environmental vulnerability. This approach further helps to understand population dynamics in the periphery of the Roman administrative boundaries and to revise traditional archaeological narratives of large-scale population replacements during the so-called Migration Period.

Enhanced trends in spectral greening and climate anomalies across Europe.

Europe witnessed a strong increase in climate variability and enhanced climate-induced extreme events, such as hot drought periods, mega heat waves, and persistent flooding and flash floods. Intensified land degradation, land use, and landcover changes further amplified the pressure on the environmental system functionalities and fuelled climate change feedbacks. On the other hand, global satellite observations detected a positive spectral greening trend-most likely as a response to rising atmospheric CO2 concentrations and global warming. But which are the engines behind such shifts in surface reflectance patterns, vegetation response to global climate changes, or anomalies in the environmental control mechanisms? This article compares long-term environmental variables (1948-2021) to recent vegetation index data (Normalized Difference Vegetation Index (NDVI), 2001-2021) and presents regional trends in climate variability and vegetation response across Europe. Results show that positive trends in vegetation response, temperature, rainfall, and soil moisture are accompanied by a strong increase in climate anomalies over large parts of Europe. Vegetation dynamics are strongly coupled to increased temperature and enhanced soil moisture during winter and the early growing season in the northern latitudes. Simultaneously, temperature, precipitation, and soil moisture anomalies are strongly increasing. Such a strong amplification in climate variability across Europe further enhances the vulnerability of vegetation cover during extreme events.

Take a seed! Revealing Neolithic landscape and agricultural development in the Carpathian Basin through multivariate statistics and environmental modelling.

The Carpathian Basin represents the cradle of human agricultural development during the Neolithic period, when large parts were transformed into 'cultural landscapes' by first farmers from the Balkans. It is assumed that an Early Neolithic subsistence economy established along the hydrologic systems and on Chernozem soil patches, which developed from loess deposits. However, recent results from soil chemistry and geoarchaeological analyses raised the hypothesis that extensive Chernozem coverage developed from increased land-use activity and that Early Neolithic 'cultural' groups were not restricted to loess-covered surfaces but rather preferred hydromorphic soils that formed in the floodplains. This article performs multivariable statistics from large datasets of Neolithic sites in Hungary and allows tracing Early to Late Neolithic site preferences from digital environmental data. Quantitative analyses reveal a strong preference for hydromorphic soils, a significant avoidance of loess-covered areas, and no preference for Chernozem soils throughout the Early Neolithic followed by a strong transformation of site preferences during the Late Neolithic period. These results align with socio-cultural developments, large-scale mobility patterns, and land-use and surface transformation, which shaped the Carpathian Basin and paved the way for the agricultural revolution across Europe.

Tracing mobility patterns through the 6th-5th millennia BC in the Carpathian Basin with strontium and oxygen stable isotope analyses.

The complexity of Neolithic population movements and their interpretation through material culture have been the subject of archaeological research for decades. One of the dominant narratives proposes that groups from the Starcevo-Körös-Cris complex spread from the central towards the northern Balkans in the Early Neolithic and eventually brought the Neolithic lifestyle into present-day Hungary. Broad geographical migrations were considered to shape the continuous expansion of Neolithic groups and individuals. However, recent archaeological research, aDNA, and isotope analyses challenged the synchronous appearance of specific material culture distributions and human movement dynamics through emphasizing communication networks and socio-cultural transformation processes. This paper seeks to retrace the complexity of Neolithic mobility patterns across Hungary by means of strontium and oxygen stable isotope analyses, which were performed on a total of 718 human dental enamel samples from 55 Neolithic sites spanning the period from the Starcevo to the Balaton-Lasinja culture in Transdanubia and from the Körös to the Tiszapolgár cultural groups on the Great Hungarian Plain (Alföld). This study presents the largest strontium and oxygen isotope sample size for the Neolithic Carpathian Basin and discusses human mobility patterns on various geographical scales and throughout archaeological cultures, chronological periods, and sex and gender categories in a multiproxy analysis. Based on our results, we discuss the main stages of the Neolithisation processes and particularly trace individual movement behaviour such as exogamy patterns within extensive social networks. Furthermore, this paper presents an innovative differentiation between mobility patterns on small, micro-regional, and supra-regional scales, which provides new insights into the complex organisation of Neolithic communities.

Intestinal transit and systemic metabolism of apple polyphenols.

BACKGROUND: Apples are the most widely consumed fruits in Germany and various other countries. Positive health effects of apple-derived polyphenols in vivo depend on their absorption, metabolism, distribution, and elimination from the body after consumption. Data on the metabolism of these polyphenols in humans are scarce. In order to study the intestinal transit and metabolism of apple polyphenols in humans, a variety of experiments were carried out. METHODS: Polyphenols were incubated with saliva (for 5 min), simulated gastric or duodenal juice (4 or 10 h, respectively), or rat hepatocytes (4 h) under aerobic conditions, and with ileostomy fluid under aerobic conditions for 10 h. The polyphenol profile in human serum (8 h later) and renal elimination in urine (24 h later) were also investigated after consumption of 1 L apple juice. Polyphenols and their metabolites were identified and quantified by high-performance liquid chromatography with diode array detection (HPLC-DAD), HPLC-electrospray ionization-tandem mass spectrometry (ESI-MS/MS), and gas chromatography (GC)-MS. RESULTS: In the presence of native saliva or ileostomy fluid, ß-glycosides of phloretin and quercetin were hydrolyzed, to varying degrees depending on the sugar moiety, and to much lesser degrees in the presence of antibiotics. In the gastric milieu, almost complete degradation of procyanidin B(2) to (-)-epicatechin was observed. In the presence of artificial duodenal juice flavan-3-ol epimerization occurred. Quercetin was completely converted to phloroglucinol, 3,4-dihydroxybenzoic acid, and 2,4,6-trihydroxybenzoic acid. Formation of isomeric products of hydroxycinnamic acid esters and their corresponding methyl esters was also observed, and similar results were obtained after incubation with rat hepatocytes. Products of phase II metabolism, two phloretin O-glucuronides and eight (methyl) quercetin O-glucuronides, were identified in the hepatocyte samples. Following enzymatic hydrolysis, 5-caffeoylquinic acid, 4-p-coumaroylquinic acid, caffeic acid, (-)-epicatechin, phloretin, and quercetin were recovered in both serum and urine (5.3% and 3.5% of the amounts consumed, respectively). In addition, 19.5% of the polyphenols consumed were identified in the urine in the form of hydroxylated phenolic and hippuric acids. CONCLUSION: The findings relating to the absorption, metabolism, and systemic availability of polyphenols in vivo should contribute to our understanding of their biological effects, and the characterization of newly formed metabolites should facilitate further studies.

Pyrrolizidine alkaloids in pollen and pollen products.

Recently, 1,2-dehydropyrrolizidine alkaloid (PA) ester alkaloids, found predominantly as their N-oxides (PANOs, pyrrolizidine N-oxides), have been reported in both honey and in pollen obtained directly from PA plants and pollen loads collected by bees, raising the possibility of health risks for consumers of these products. We confirm these findings in regard to floral pollen, using pollen collected directly from flowers of the known PA plants Senecio jacobaea, S. vernalis, Echium vulgare and pollinia of Phalaenopsis hybrids, and we extend analyses of 1,2-unsaturated PAs and 1,2-unsaturated PANOs to include bee-pollen products currently being sold in supermarkets and on the Internet as food supplements. PA content of floral pollen ranged from 0.5 to 5 mg/g. The highest values were observed in pollen obtained from Senecio species. Up to 95% of the PAs are found as PANOs. Detailed studies with S. vernalis revealed unique PA patterns in pollen and flowers. While seneciphylline was the most prominent PA in S. vernalis pollen, the flowers were dominated by senecionine. To analyze trace amounts of 1,2-unsaturated PAs in pollen products, our previously elaborated method consisting of strong cation exchange-SPE, two reduction steps followed by silylation and subsequent capillary high-resolution GC-MS using SIM mode was applied. In total, 55 commercially available pollen products were analyzed. Seventeen (31%) samples contained 1,2-unsaturated PAs in the range from 1.08 to 16.35 microg/g, calculated as retronecine equivalents. The 1,2-unsaturated PA content of pollen products is expressed in terms of a single sum parameter and no background information such as foraged plants, pollen analysis, etc. was needed to analyze the samples. The detection limit of overall procedure and the reliable quantitation limit were 0.003 and 0.01 microg/g, respectively.

Pyrrolizidine alkaloids (PAs) in honey and pollen-legal regulation of PA levels in food and animal feed required.

Pyrrolizidine alkaloids (PAs) are secondary plant constituents that comprise about 400 different structures and occur in two major forms, a tertiary form and the corresponding N-oxide. PAs containing a 1,2-double bond are pre-toxins and metabolically activated by the action of hepatic P-450 enzymes to toxic pyrroles. Besides the acute toxic effects, the genotoxic and tumorigenicity potential of PAs was demonstrated in some eukaryotic model systems. Recently, the potential PA contamination of food and feeding stuff attracted recurrent great deals of attention. Humans are exposed to these toxins by consumption of herbal medicine, herbal teas, dietary supplements or food containing PA plant material. In numerous studies the potential threat to human health by PAs is stated. In pharmaceuticals, the use of these plants is regulated. Considering the PA concentrations observed especially in authentic honey from PA producing plants and pollen products, the results provoke an international regulation of PAs in food.

Anionic Synthesis and Rheological Characterization of Poly(p-methylstyrene) Model Comb Architectures with a Defined and Very Low Degree of Long Chain Branching.

A method is presented for the synthesis of defined sparsely branched polystyrene-based homopolymer model combs. By the use of poly(p-methylstyrene) (PpMS) as backbone and side chains, a low, but well controlled amount of branching of typically less than 1 mol-% (e.g., 1 branch per approx. 200 backbone C-atoms) can be achieved. The used anionic synthesis offers full control of the molecular weight in combination with low polydispersity. Molecular weight and polydispersity were determined by SEC-MALLS, confirming the well defined synthesis with low polydispersity ($\overline {{\rm M}} _{{\rm w}} /\overline {{\rm M}} _{{\rm n}} $ < 1.07). The melt rheological properties of the synthesized linear and comb polymers were obtained in both oscillatory shear and uniaxial extensional flow. Using the so-called van Gurp-Palmen plot, clear differences between both synthesized topologies are clearly seen. The appearance of a second minimum for lower values of the complex modulus in shear is a clear indication of a second relaxation process attributable to the entangled side chains. The presence of the entangled side chains is responsible for the observed strain hardening obtained in extensional viscosity experiments, as compared to the linear polymers. These model samples open up the possibility to compare different advanced rheological methods, e.g., FT-rheology or extensional rheology, towards limiting sensitivity.

Feeding deterrence and detrimental effects of pyrrolizidine alkaloids fed to honey bees (Apis mellifera).

Recent studies have shown the occurrence of plant derived pyrrolizidine alkaloids (PAs) in retail honeys and pollen loads, but little is known about how these compounds influence the fitness of foraging honey bees. In feeding experiments, we tested a mix of tertiary PAs and the corresponding N-oxides from Senecio vernalis, pure monocrotaline, and 1,2-dihydromonocrotaline in 50% (w/w) sucrose solutions. The bees were analyzed chemically to correlate the observed effects to the ingested amount of PAs. PA-N-oxides were deterrent at concentrations >0.2%. 1,2-Unsaturated tertiary PAs were toxic at high concentrations. The observed PAs mortality could be linked directly to the presence of the 1,2-double bond, a well established essential feature of PA cytotoxicity. In contrast, feeding experiments with 1,2-dihydromonocrotaline revealed no toxic effects. Levels of less than 50 microg 1,2-unsaturated tertiary PAs per individual adult bee were tolerated without negative effects. PA-N-oxides fed to bees were reduced partially to the corresponding tertiary PAs. Unlike some specialized insects, bees are not able to actively detoxify PAs through N-oxidation. To gain insight into how PAs are transmitted among bees, we tested for horizontal PA transfer (trophallaxis). Under laboratory conditions, up to 15% of an ingested PA diet was exchanged from bee to bee, disclosing a possible route for incorporation into the honey comb. In the absence of alternative nectar and pollen sources, PA-containing plants might exhibit a threat to vulnerable bee larvae, and this might affect the overall colony fitness.

Online gas chromatography combustion/pyrolysis-isotope ratio mass spectrometry (HRGC-C/P-IRMS) of (+/-)-Dihydroactinidiolide from tea ( Camellia sinensis ) and rooibos tea ( Aspalathus linearis ).

Online capillary gas chromatography-isotope ratio mass spectrometry in both the combustion and the pyrolysis modes (HRGC-C/P-IRMS) was employed to perform authentication studies of the flavoring agent (+/-)-dihydroactinidiolide. Thus, the delta(13)C(V-PDB) and delta(2)H(V-SMOW) values of synthetic (ex synthetic beta-ionone and natural beta-carotene) as well as enzymatically (ex synthetic and natural beta-carotene) produced references were studied in comparison with those of the natural substance isolated from black (n = 17) and green teas (n = 6) ( Camellia sinensis ) as well as Rooibos tea ( Aspalathus linearis ) (n = 7). The isotope values determined for both the synthetic and enzymatically produced samples of (+/-)-dihydroactinidiolide reflected the influence of the origin of their educts. Hence, in cases when synthetic educts were used, the delta(13)C(V-PDB) and delta(2)H(V-SMOW) values ranged from -27.0 to -28.4 per thousand and from -28 to -169 per thousand, respectively, whereas the use of natural educts led to ranges from -30.3 to -31.6 per thousand and from -154 to -228 per thousand, respectively. As to the tea samples, delta(13)C(V-PDB) and delta(2)H(V-SMOW) values ranging from -29.0 to -34.1 per thousand and from -153 to -274 per thousand, respectively, were recorded for (+/-)-dihydroactinidiolide from black and green teas, whereas that from Rooibos tea showed (2)H/(1)H ratios ranging from -189 to -210 per thousand as well as slightly enriched values in the (13)C/(12)C ratios ranging from -24.4 to -27.1 per thousand.

Pyrrolizidine alkaloids in honey: risk analysis by gas chromatography-mass spectrometry.

Recently, contamination of honey with pyrrolizidine alkaloids (PA) has been reported as potential health risk. Therefore, it was of interest to develop a reliable tool for selective and quantitative determination of PA in honey. Sample preparation of the novel method comprises strong cation exchange SPE (SCX-SPE), followed by two reduction steps using zinc and LiAlH(4), as well as subsequent silylation. During this procedure the separated PA are converted into the necin backbone, the common structural feature of PA toxicity, which is analyzed by GC-MS in the SIM mode. The procedure was validated using PA from extracts of Senecio vernalis as well as authentic PA standards including their corresponding N-oxides. The PA content of honey samples was quantified with heliotrine as internal standard. The method was applied to generate a dataset in order to evaluate the potential risk of PA contamination especially for retail honeys available on the German/European market. No selection criteria in terms of floral or geographical origin were applied on the samples before analysis. In total, 216 commercially available floral honey samples were analyzed. Among them 19 samples contained PA, in the range of 0.019-0.120 microg/g, calculated as retronecine equivalents. The reported method facilitates the selective determination of PA without the need to identify each individual PA independently. The PA contamination of honey is expressed in terms of a single sum parameter and no background information such as foraged plants and pollen analysis is necessary. The LOQ is 0.01 ppm with a S/N of 7:1.

Model experiments mimicking the human intestinal transit and metabolism of D-galacturonic acid and amidated pectin.

In order to study the human intestinal transit and metabolism of D-galacturonic acid and amidated pectin a number of model experiments were carried out. Both substrates were incubated under aerobic conditions at 37 degrees C using saliva (2 min) and simulated gastric juice (4 h). Under anaerobic conditions the substrates were incubated at 37 degrees C using human ileostomy and colostomy fluids, each obtained from three different donors, for 10 and for 24 h, respectively. D-Galacturonic acid, SCFA (acetic acid, propionic acid, and butyric acid), as well as methanol were analyzed photometrically after carbazole reaction, GC-flame ionization detection (GC-FID), and headspace solid-phase microextraction GC/MS (HS-SPME-GC/MS), respectively. D-Galacturonic acid and amidated pectin were found to be stable during incubations with saliva and simulated gastric juice, whereas both substrates underwent degradation in the course of human ileostomy and colostomy fluid incubations. D-Galacturonic acid was practically completely decomposed within 10 h and SCFA, with acetic acid as the major representative, were formed up to 98% of the incubated substrate in colostomy effluent. The amidated pectin was only degraded in part, revealing stable amounts of 22-35% and 3-17% in ileostomy (after 10 h) and colostomy fluid (after 24 h), respectively. SCFA were generated up to 59% of the applied amidated pectin. In parallel, 19-60% and 52-67% of the available methyl ester groups were cleaved in the course of incubations with ileostomy and colostomy fluids, respectively. The results demonstrate for the first time that D-galacturonic acid and amidated pectin are stable in human saliva and simulated gastric juice. The degradation of both compounds during incubation with ileostomy effluent is highlighted, providing evidence for a considerable metabolic potential of the small intestine.

Polyphenols are intensively metabolized in the human gastrointestinal tract after apple juice consumption.

Polyphenols are secondary plant compounds showing anticarcinogenic effects both in vitro and in animal experiments and may thus reduce the risk of colorectal cancer in man. The identification of polyphenol metabolites formed via their passage through the small intestine of healthy ileostomy subjects after apple juice consumption is presented. Identification and quantification of polyphenols and their metabolites were performed using HPLC-DAD as well as HPLC-ESI-MS/MS. Total procyanidin content (TPA) was measured, and additionally the mean degree of polymerization (DPm) of the procyanidins was determined in the apple juice and ileostomy effluents. As products of polyphenol metabolism, D-(-)-quinic acid and methyl esters of caffeic acid and p-coumaric acid are liberated from the corresponding hydroxycinnamic acid esters. 1-Caffeoylquinic acid and 3-caffeoylquinic acid were determined as products of isomerization. Phloretin 2'-O-glucoside (phloridzin) and phloretin 2'-O-xyloglucoside were metabolized into the corresponding aglycons phloretin and phloretin 2'-O-glucuronide and all were found in the ileostomy effluent. Ninety percent of the consumed procyanidins were recovered in the ileostomy effluent and therefore would reach the colon under physiologic circumstances. The DP m was reduced (DP m of apple juice=5.7) and varied depending on the time point of excretion. The gastrointestinal passage seems to play an important role in the colonic availability of apple polyphenols.

Flavor authentication studies of alpha-ionone, beta-ionone, and alpha-ionol from various sources.

In addition to the already available information on the authenticity of alpha- (1) and beta-ionone (2) from plant tissues, there is an interest in the stable isotope data of 1 and 2 available by synthesis from citral and acetone, as European Union regulations, in contrast to the United States and other countries, do not allow a product to be declared as 'natural' that has been chemically synthesized (e.g., by using a natural catalyst) from natural educts. Analyses performed by on-line capillary gas chromatography-isotope ratio mass spectrometry in the combustion and pyrolysis modes (HRGC-C/P-IRMS) as well as by elemental analyzers (EA-C/P-IRMS) measuring delta(13)C(V)-PDB and delta(2)H(V)-SMOW values provide for the first time isotope data of such 'natural' 1 and 2 as well as of synthetic and 'ex plant' alpha-ionol (3). The isotope data recorded for synthesized 1 and 2 reflected the influence of the origin of the used citral, whereas that of acetone was less remarkable. For instance, 'natural' 1 ex citral from lemongrass showed, as expected for a C4 plant, an enriched delta(13)C(V)-PDB value of -18.5 per thousand. In addition, the use of synthetic citral resulted in an enriched delta(2)H(V)-SMOW value of -43 per thousand, whereas with citral ex Litsea cubeba and ex lemongrass values of -242 and -232 per thousand, respectively, were recorded. IRMS analyses of 'natural' 2 revealed delta(13)C(V)-PDB and delta(2)H(V)-SMOW values that were nearly identical to that recorded for 'natural' 1. As to both 1 and 2, variations of synthesis conditions led to distinct changes in the delta(13)C(V)-PDB but not the delta(2)H(V)-SMOW values. Synthetic 3 showed delta(13)C(V)-PDB and delta(2)H(V)-SMOW values of -24.5 and -184 per thousand, respectively. These data differed from those found in raspberry fruit under study (n = 8), that is, ranging from -33.6 to -36.6 per thousand for delta(13)C(V)-PDB and from -200 to -225 per thousand for delta(2)H(V)-SMOW. The values determined additionally for 1 and 2 in raspberry fruit samples ranged from -30.3 to -35.1 per thousand and from -176 to -221 per thousand for delta(13)C(V)-PDB and delta(2)H(V)-SMOW, respectively, and thus corresponded to the already known literature information.

Microbial diversity of Indian Ocean hydrothermal vent plumes: microbes tolerant of desiccation, peroxide exposure, and ultraviolet and gamma-irradiation.

The microbial diversity of Kali chimney plumes, part of a hydrothermal vent field in the Rodriguez Triple Junction, Indian Ocean (depth approximately 2,240 m), was examined in an attempt to discover "extremotolerant" microorganisms that have evolved unique resistance capabilities to this harsh environment. Water and sediment samples were collected from the vent and from sediments located at various distances (2-20 m) away from and surrounding the chimney. Samples were screened for hypertolerant microbes that are able to withstand multiple stresses. A total of 46 isolates were selected for exposure to a number of perturbations, such as heat shock, desiccation, H(2)O(2), and ultraviolet (UV) and gamma-irradiation. The survival of Psychrobacter sp. L0S3S-03b following exposure to >1,000 J/m(2) UV(254) radiation was particularly intriguing amid a background of varying levels of resistance. Vegetative cells of this non-spore-forming microbe not only survived all of the treatments, but also exhibited a 90% lethal dose of 30 s when exposed to simulated martian UV radiation and a 100% lethal dose of 2 min when exposed to full spectrum UV, which is comparable to findings for bacterial endospores.

Urinary 2-ethyl-3-oxohexanoic acid as major metabolite of orally administered 2-ethylhexanoic acid in human.

Human metabolism of 2-ethylhexanoic acid (2-EHA), which is a known metabolite of important phthalates, was investigated using 2-EHA-contaminated food. The results of our studies reveal that the major catabolic pathway of 2-EHA in human is beta-oxidation. The dominant final urinary metabolite was identified and quantified as 3-oxo-2-ethylhexanoic acid (3-oxo-2-EHA), but only after immediate methylation of the extract from urine and prior to GC-MS analysis. Former studies without the precaution of immediate methylation had found 4-heptanone as the major metabolite, which is obviously an artifact arising from the decarboxylation of 3-oxo-2-EHA.