Biomarkers in turbidites at ODP Sites 157-951 and 157-952

Free and ester-bound lipid biomarkers were analysed in oxidised and unoxidised parts of four distinct turbidites from the Madeira Abyssal Plain (MAP), which contained 1 to 2% organic carbon homogeneously distributed throughout the turbidites at the time they were deposited. These turbidites are well suited to study the effects of oxic degradation on lipid biomarkers without the complicating influence of varying organic matter sources, sedimentation rates, or bioturbation. One sample from the oxidised turbidite was compared with two samples from the unoxidised part of each turbidite. Postdepositional oxic degradation decreased concentrations of biomarkers by several orders of magnitude. The ester-bound lipids were degraded to a far lesser extent than their free counterparts were. The extent of degradation of different compounds differed substantially. Within a specific class of biomarkers, degradation also took place to a different extent, altering their distributions. This study shows that oxic degradation of the organic matter may have a profound effect on the biomarker fingerprint and may result in a severe bias in, for example, the interpretation of organic matter sources and the estimation of the palaeoproductivity of specific groups of phytoplankton.

Molecular and isotopic compositions of hydrocarbons at DSDP Site 76-533

In an investigation of gas hydrates in deep ocean sediments, gas samples from Deep Sea Drilling Project Site 533 on the Blake Outer Ridge in the northwest Atlantic were obtained for molecular and isotopic analyses. Gas samples were collected from the first successful deployment of a pressure core barrel (PCB) in a hydrate region. The pressure decline curves from two of the four PCB retrievals at in situ pressures suggested the presence of small amounts of gas hydrates. Compositional and isotopic measurements of gases from several points along the pressure decline curve indicated that (1) biogenic methane (d13C = -68 per mil; C1/C2 = 5000) was the dominant gas (>90%); (2) little fractionation in the C1/C2 ratio or the C carbon isotopic composition occurred as gas hydrates decomposed during pressure decline experiments; (3) the percent of C3, i-C4, and CO2 degassed increased as the pressure declined, indicating that these molecules may help stabilize the hydrate structure; (4) excess nitrogen was present during initial degassing; and (5) C1/C2 ratios and isotopic ratios of C gases were similar to those obtained from conventional core sampling. The PCB gas also contained trace amounts of saturated, acyclic, cyclic, and aromatic C5-C14 hydrocarbons, as well as alkenes and tetrahydrothiophenes. Gas from a decomposed specimen of gas hydrate had similar molecular and isotopic ratios to the PCB gas (d13C of -68 per mil for methane and a C1/C2 ratio of about 6000). Regular trends in the d13C of methane (about -95 to -60 per mil) and C1/C2 ratios (about 25000 to 2000) were observed with depth. Capillary gas chromatography (GC) and total scanning fluorescence measurements of extracted organic material were characteristic of hydrocarbons dominated by a marine source, though significant amounts of perylene were also present.

Biogeochemical parameters and processes in waters and bottom sediments of the Chukchi Sea

Study of biogeochemical processes in waters and sediments of the Chukchi Sea in August 2004 revealed atypical maxima of biogenic element (N, P, and Si) concentrations and rate of microbial sulfate reduction in the surface layer (0-3 cm) of marine sediments. The C/N/P ratio in organic matter (OM) of this layer does not fit the Redfield-Richards stoichiometric model. Specific features of biogeochemical processes in the sea are likely related to the complex dynamics of water, high primary produc¬tivity (110-1400 mg C/m**2/day), low depth of the basin (<50 m for 60% of the water area), reduced food chain due to low population of zooplankton, high density of zoobenthos (up to 4230 g/m**2), and high activity of microbial processes. Drastic decrease in concentrations of biogenic elements, iodine, total alkalinity, and population of microorganisms beneath the 0-3 cm layer testify to large-scale OM decay at the water-seafloor barrier. Our original experimental data support high annual rate of OM mineralization at the bottom of the Chukchi Sea.

Age model and chemistry of sediment core STK7 from Steisslinger See

Stable isotope records for carbon and oxygen in bulk carbonates, carbon in bulk organic matter, and for total and chromium-reducible sulfur in a lacustrine sediment core from Lake Steisslingen (Southwest Germany) show several distinct and abrupt shifts during the last 15,000 years. Variations in the isotopic composition of authigenic carbonates indicate two major phases in the lake history. In the pre-Holocene, the hydrological budget of the lake was apparently stable. Variations of delta18O values of authigenic carbonates were, therefore, dominantly controlled by temperature changes. A decrease in the delta18Ocarb values of about 2 per mil at the Allerød/Younger Dryas transition is interpreted as a drop in mean annual air temperatures of approximately 5°C. An abrupt temperature increase of a similar magnitude is inferred at the Younger Dryas/Preboreal boundary. Throughout most of the Holocene, the isotopic composition of authigenic carbonates was influenced by marked changes in the hydrological budget of the lake. A major positive excursion in the delta13Ccarb and delta18Ocarb values at the beginning of the Atlantic and a smaller one in the Preboreal were related to evaporation effects, which indicate that dry climatic conditions must have prevailed at that time. A simultaneous increase in delta13C values of bulk organic matter at the beginning of the Atlantic suggests a high level of productivity in the lake. As a consequence, aqueous sulfate became limited as indicated by variations in the delta34S values of total and chromium-reducible sedimentary sulfur. Therefore, we conclude that the beginning of the Atlantic was characterized not only by dry but also by warm climatic conditions, which triggered a higher productivity in the lake. In the Subatlantic sediments, large variations in carbon, oxygen, and sulfur isotope ratios were observed as a result of human activities, causing considerable perturbations in the biogeochemical element cycling of Lake Steisslingen. Results obtained by the study of the continuous 15 ka record of Lake Steisslingen document clearly that isotopic proxy data from lacustrine sediments can provide useful information on environmental and climatic changes of local, regional, and in the case of the Younger Dryas event, of even hemispherical significance.

Geochemical investigations of sediment profiles in the Norwegian-Greenland Sea

High-, i.e. 15-140-yr-resolution climate records from sediment cores 23071, 23074, and PS2644 from the Nordic Seas were used to recon:;truct changes in the surface and deep water circulation during marine isotope stages 1-5.1, i.e. the last 82 000 yr. From this the causal links between the paleoceanographic signals and the Dansgaard-Oeschger events 1-21 revealed in 0180-ice-core records from Greenland were determined. The stratigraphy of the cores is based on the planktic 0180 curves, the minima of which were directly correlated with the GISP2-0180 record, numerous AMS 14C ages, and some ash layers. The planktic d18O and dl3C curves of all three cores reveal numerous meltwater events, the most pronounced of which were assigned to the Heinrich events 1-6. The meltwater events, among other things also accompanied by cold sea surface temperatures and high IRD concentration, correlate with the stadial phases of the Dansgaard-Oeschger cycles and in the western Iceland Sea also to colder periods or abrupt drops in 0180 within a few longer interstadials. Besides being more numerous, the meltwater events also show isotope values lighter in the Iceland Sea than in the central Norwegian Sea, especially if compared to core 23071. This implies a continuous inflow of relative warm Atlantic water into the Norwegian Sea and a cyclonic circulation regime.

The management of bone tools from the Bronze Age site of El Portalón of Cueva Mayor, Sierra de Atapuerca, Burgos

In this paper we analyze the set of Bronze Age bone tools recovered at the archaeological site of El Portalón of Cueva Mayor in the Sierra de Atapuerca (Burgos). The Bronze Age cultural period is the best represented in the cavity and its study has forced us to unify the different excavation and stratigraphical criteria undertaken from the earliest archaeological excavations developed by J.M. Apellániz during the 70s until the excavations of the current research team (EIA) since 2000. We propose here for the first time a relationship between the initial system of “beds” used by Apellániz and our recent sedimentary sequence that recognizes eleven stratigraphic levels radiometrically dated from the late Upper Pleistocene to the Middle Age. Within the bone industry assemblage we recognize a large variety of utensils and ornamental elements, with native and allochthonous features, that make evident a regional as well as long distance relationships of these populations of the interior of the Iberian Peninsula during the recent Prehistory.

Argaric Sociology: Sex and Death

The detailed, rich and diverse Argaric funerary record offers an opportunity to explore social dimensions that usually remain elusive for prehistoric research, such us social rules on kinship rights and obligations, sexual tolerance and the role of funerary practices in preserving the economic and political organization. This paper addresses these topics through an analysis of the social meaning of Argaric double tombs by looking at body treatment and composition of grave goods assemblages according to gender and class affiliation. The Argaric seems to have been a conservative society, scarcely tolerant regarding homosexuality, and willing to celebrate ancestry associated to certain places as a means of asserting residence and property rights.

Nonparametric tests of collectively rational consumption behavior: an integer programming procedure

We present an IP-based nonparametric (revealed preference) testing procedure for rational consumption behavior in terms of general collective models, which include consumption externalities and public consumption. An empirical application to data drawn from the Russia Longitudinal Monitoring Survey (RLMS) demonstrates the practical usefulness of the procedure. Finally, we present extensions of the testing procedure to evaluate the goodness-of-…t of the collective model subject to testing, and to quantify and improve the power of the corresponding collective rationality tests.

Towards the total synthesis of amphidinolides C and F

The amphidinolides are marine macrolides extracted from dinoflagellates of the genus Amphidinium. To date, 37 amphidinolides have been isolated and identified, most of them possessing cytotoxicity against human cancer cell lines. Among these, amphidinolides C, F, C2 and C3 represent synthetic targets of interest owing to their scarcity, structural complexity and promising biological activities. This thesis describes the work realised towards the total synthesis of amphidinolides C and F, with a focus on the different strategies investigated and the key fragments synthesised. In the first approach, the C18−C29 fragment of amphidinolide F was prepared using an intramolecular etherification of an epoxide under acidic catalysis to produce the 2,5-trans-disubstituted tetrahydrofuran ring featured in the natural product. Unfortunately, dithiane alkylation with the C1−C17 iodide counterpart generated the desired coupling product in low yield. A second approach proposing to build the C17−C18 bond by a silicon-tethered RCM proved unsuccessful, because the requisite diene could not be obtained. It was then envisioned to form the C18−C19 bond by displacement of a triflate with an alkyne and install the ketone at C18 by a protoborylation/oxidation sequence. To this end, the C19−C29 triflate precursor was synthesised. Displeasingly, the C1−C18 alkyne counterpart (work by Dr Filippo Romiti) could not be prepared and coupling of the two fragments was not attempted. In the latest approach, the C10−C29 fragment of amphidinolide F was obtained employing a boron-mediated aldol condensation and a dithiane alkylation to form the C13−C14 and C18−C19 bonds. Several endgame strategies were examined including the successful Yamaguchi esterification of the C13-epi C10−C29 fragment and the C1−C9 acid. A challenging Stille crosscoupling was then effected to close the macrocycle but only yielded the desired macrolactone in trace amounts after global desilylation.

Oligomerization of Cry9Aa in solution without receptor binding, is not related with insecticidal activity

Background: Bacillus thuringiensis Cry toxins bind with different insect midgut proteins leading to toxin oligomerization, membrane insertion and pore formation. However, different Cry toxins had been shown to readily form high molecular weight oligomers or aggregates in solution in the absence of receptor interaction. The role of Cry oligomers formed in solution remains uncertain. The Cry9A proteins show high toxicity against different Lepidoptera, and no-cross resistance with Cry1A. Results: Cry9Aa655 protein formed oligomers easily in solution mediated by disulfide bonds, according to SDS-PAGE analysis under non-reducing and reducing conditions. However, oligomerization is not observed if Cry9Aa655 is activated with trypsin, suggesting that cysteine residues, C14 and C16, located in the N-terminal end that is processed during activation participate in this oligomerization. To determine the role of these residues on oligomerization and in toxicity single and double alanine substitution were constructed. In contrast to single C14A and C16A mutants, the double C14A–C16A mutant did not form oligomers in solution. Toxicity assays against Plutella xylostella showed that the C14A–C16A mutant had a similar insecticidal activity as the Cry9Aa655 protein indicating the oligomers of Cry9Aa formed in solution in the absence of receptor binding are not related with toxicity. Conclusions: The aggregation of Cry9Aa655 polypeptides was mediated by disulfide bonds. Cry9Aa655 C14 and C16C are involved in oligomerization in solution. These aggregate forms are not related to the mode of action of Cry9Aa leading to toxicity.

Chromatographic determination of fatty acids profiles in regionally-produced Portuguese goat cheese along curing

The biochemistry of cheese ripening involves mechanisms such as glycolysis, proteolysis and lipolysis. Fatty acids are released by the action of lipases from different sources, milk, rennet, bacteria, moulds included as secondary starters, and other exogenous lipases, during lipolysis [1]. The composition of the lipid fraction contributes positively to the flavour of cheese, for being precursors of more complex aroma compounds responsible for the characteristic “goaty flavour” of goat cheeses [2]. Goat milk is recognized by its easier digestibility, alkalinity, buffering capacity and certain therapeutic values in medicine and human nutrition [3]. A high total content of fatty acids is strongly linked to a rancid and tart off flavour in goat milk and may be considered undesirable in most cheese varieties [4]. In this sense, the purpose of the present study was to examine the composition and changes in fatty acids and saponification value of goat cheese during curing period (2, 7 and 12 months). Goat cheese was made in industrial unit of Cachão - Mirandela (Trás-os- Montes) with raw milk Serrana goats’ race, salt and rennet from animal origin. During the first two months, the samples were stored in a ripening chamber (9.5-11 °C and RH 75-85%). From the second month to one year, the samples were stored in a preservation chamber (10.5-12 °C and RH 75-85%). The fatty acids profile of the inner part of the cheese was analyzed by gas-chromatography coupled to flame ionization detection (GC-FID). The degree of saponification was determined both in the crust and inside the cheese by HCl titration of ethanol KOH solution of the samples. Twenty-six fatty acids (FA) were identified and quantified in the inner part of the cheese (total fat was 45-46 g/100 g during the curing period). Saturated fatty acids (SFA) did not change up to 7 months of curing, increasing only after 12 months, being palmitic (C16:0), stearic (C18:0), myristic (C14:0) and capric (C10:0) acids the most abundant FA in this class. Monounsaturated fatty acids (MUFA) decreased only after 12 months, and oleic acid (C18:1) was the predominant FA. In polyunsaturated fatty acids (PUFA) class, the most abundant were linoleic (C18:2) and linolenic (C18:3) acids, and followed the same tendency of MUFA. This is corroborated by an increase in the degree of saponification, either in the crust as in the inner part of the cheese, after 12 months of curing, probably related with the saturation of the fatty acids [3]. Extra-long curing can be done in cheeses produced with goat milk up to seven months of storage without changing the total fat and individual FA content.

Influência da radiação por feixe de eletrões no perfil cromatográfico de Bauhinia variegata var candida: flor comestível proveniente do brasil

As flores de Bauhinia variegata var candida apresentam coloração branca e são vulgarmente conhecidas como “patas de vaca branca”, sendo muito utilizadas na cozinha gourmet como forma de aumentar a qualidade sensorial e nutricional dos alimentos [1,2]. No presente estudo, as flores foram submetidas a radiação por feixe de eletrões em diferentes doses (0,5 e 0,8 kGy) como forma de descontaminação, e seguidamente analisadas em termos de parâmetros nutricionais (humidade, proteínas, gordura, hidratos de carbono e cinzas) e perfis em açúcares livres (HPLCRI), ácidos gordos (GC-FID), tocoferóis (HPLC-Fluorescência) e ácidos orgânicos (HPLC-DAD). As amostras não irradiadas e irradiadas mostraram um perfil nutricional semelhante, sendo os hidratos de carbono os nutrientes mais abundantes, seguidos das proteínas, gorduras e cinzas. Os perfis em açúcares foram também similares, estando presente a frutose em maior quantidade, seguida da glucose e da sacarose. Os ácidos mirístico (C14:0), palmítico (C16:0), esteárico (C18:0) e oleico (C18:1n9), foram os ácidos gordos mais abundantes. Os ácidos gordos saturados (SFA) foram os mais abundantes, seguidos dos mono (MUFA) e polinsaturados (PUFA). Neste caso, com maior dose de radiação verificou-se que a percentagem de SFA e MUFA diminui ligeiramente (principalmente pelo aumento dos ácidos esteárico e oleico, respetivamente), aumentando a percentagem de PUFA (principalmente pelo aumento dos ácidos linoleico e α-linolénico). No que respeita aos tocoferóis, só a isoforma α foi encontrada, apresentando aproximadamente o mesmo conteúdo nas amostras irradiadas e não irradiadas (1,75±0,06 mg/mL). O ácido cítrico foi o ácido orgânico mais abundante nas amostras, seguido dos ácidos: málico, ascórbico, oxálico e fumárico. Também neste caso os valores mantiveram-se, com exceção do ácido cítrico que aumentou ligeiramente com as doses de irradiação (55,94, 61,70 e 67,64 mg/mL, respetivamente). Em síntese, verificou-se que as doses de irradiação aplicadas não alteraram significativamente a composição química das amostras em estudo, e pode ser considerada uma técnica de descontaminação e preservação de flores comestíveis.

An Afriat theorem for the collective model of household consumption

We provide a nonparametric 'revealed preference’ characterization of rational household behavior in terms of the collective consumption model, while accounting for general (possibly non-convex) individual preferences. We establish a Collective Axiom of Revealed Preference (CARP), which provides a necessary and sufficient condition for data consistency with collective rationality. Our main result takes the form of a ‘collective’ version of the Afriat Theorem for rational behavior in terms of the unitary model. This theorem has some interesting implications. With only a finite set of observations, the nature of consumption externalities (positive or negative) in the intra-household allocation process is non-testable. The same non-testability conclusion holds for privateness (with or without externalities) or publicness of consumption. By contrast, concavity of individual utility functions (representing convex preferences) turns out to be testable. In addition, monotonicity is testable for the model that assumes all household consumption is public.

PALEOSUELOS Y 40KY PRESENTES EN LA PENDIENTE EN EL ESTADO CENTRO-SUR DE PARANÁ, BRASIL - UN ESTUDIO DE CASO

Centro del estado en El Sur del Paraná (segunda meseta del Paraná) fueron identificados en depósitos de talud del Cuaternario denominados Monjolo. Esto lo que extiende fuera de su Ladera conmigo acerca de 586,79 perfil convexo ha - recta y en promedio sí convierten cóncavo- recta Pendiente de la baja. En Este sector de la Pendiente Una Incisión se lleva a cabo (banco) que Expuesta la instancia de parte del Cuerpo sedimentarios y edafológicos. Las paredes expuestas FUE Posible Por la erosión identificar tres paleosuelos sepultados Bajo Niveles de aproximadamente 1,80 m de sedimentos Consuelo y el. Desde esta Sección FUE Afloramiento construido para identificar sistemáticamente Las Manera y distinguir pedossedimentares paleosuelos y en las unidades El Afloramiento presente. El objetivo es caracterizar e identificar a entender paleosuelos geomorfológica del Cuaternario La Evolución de la Pendiente de estudio. Descripciones LOS RESULTADOS del partícula tamaño combinado, la topografía, y la macro y mesoscópico Datación C14 palaeosol que muestran la Cuenta Con Más de 44 Ky.