Development of estimates of dietary nitrates, nitrites, and nitrosamines for use with the short willet food frequency questionnaire

<p>Abstract</p> <p>Background</p> <p>Studies have suggested that nitrates, nitrites, and nitrosamines have an etiologic role in adverse pregnancy outcomes and chronic diseases such as cancer. Although an extensive body of literature exists on estimates of these compounds in foods, the extant data varies in quality, quantified estimates, and relevance.</p> <p>Methods</p> <p>We developed estimates of nitrates, nitrites, and nitrosamines for food items listed in the Short Willet Food Frequency Questionnaire (WFFQ) as adapted for use in the National Birth Defects Prevention Study. Multiple reference databases were searched for published literature reflecting nitrate, nitrite, and nitrosamine values in foods. Relevant published literature was reviewed; only publications reporting results for items listed on the WFFQ were selected for inclusion. The references selected were prioritized according to relevance to the U.S. population.</p> <p>Results</p> <p>Based on our estimates, vegetable products contain the highest levels of nitrate, contributing as much as 189 mg/serving. Meat and bean products contain the highest levels of nitrites with values up to 1.84 mg/serving. Alcohol, meat and dairy products contain the highest values of nitrosamines with a maximum value of 0.531 μg/serving. The estimates of dietary nitrates, nitrites, and nitrosamines generated in this study are based on the published values currently available.</p> <p>Conclusion</p> <p>To our knowledge, these are the only estimates specifically designed for use with the adapted WFFQ and generated to represent food items available to the U.S. population. The estimates provided may be useful in other research studies, specifically in those exploring the relation between exposure to these compounds in foods and adverse health outcomes.</p

New insights into the Triassic sedimentary environment of the eastern parts of the Song Da and Sam Nua basins alongside the Indosinian Song Ma suture, Northern Vietnam

This study documents the sedimentology, structures, and foraminifer content of Triassic formations from the eastern part of the Truong Son Belt (Northern Vietnam). Sedimentary rocks in the eastern Song Da and Sam Nua basins occur on both sides of the Middle Triassic Song Ma suture zone that separates the Indochina Block from the South China Block. The main outcomes of our study include detailed stratigraphic successions that we have established for the two basins. New foraminifer determinations indicate a Middle to Late Triassic age for the carbonate deposition. The depositional settings of the carbonate deposits and their deformation patterns support a southward “subduction” beneath the Indochina Block, ending with the collision with the South China Block during the Middle Triassic. Moreover, our new biostratigraphic dating of the stratigraphic successions can be used to compare the Triassic carbonate platforms from Northern Vietnam with other platforms elsewhere, including those that have already been well documented in Indonesia

The Devonian\u2013Carboniferous boundary in the stratotype area (SE Montagne Noire, France)

Sections with continuous sedimentation across the Devonian\u2013Carboniferous (D-C) boundary in the Montagne Noire allow to build a virtual transect from shoreline to deep basin. Nearshore facies characterise the D-C boundary stratotype and neighbouring sections at La Serre in the Cabri\ue8res klippen domain, and offshore facies are present at the Col de Tribes and Puech de la Suque sections in the Mont Peyroux nappe domain. Both domains exhibit equivalents of the Hangenberg Black Shale (HBS). At La Serre, an initial regressive trend is indicated by the presence of oculated trilobites in the topmost pre-HBS Wocklumeria Limestones. Above the HBS level, regressive depositional conditions characterise oolitic deposits that comprise lithic erosional flows with an admixture of transported shallow-water biotas. Maximum regression is recognised with the deposition of coarse breccias and local features of emergence prior to the first appearance of Protognathodus kockeli. The oolites are superseded by the transgression of outer shelf deposits. In the nappe domain, the HBS is intercalated in outer ramp nodular limestones, and it exhibits detrital elements pointing to its regressive nature. The regressive trend culminates than reverses when post-HBS carbonate sedimentation resumes. Protognathodus kockeli appears in the post-HBS carbonates. Associated oculated trilobites indicate shallower bathymetric conditions then those of the pre-HBS Wocklumeria Limestones. Thereafter, replacement of sighted trilobites by blind ones and the protognathodid biofacies by facies dominated by siphonodellids indicate a deepening trend. The near- and offshore sites of the D-C transition permit correlation of short-term bathymetric fluctuations with faunal turnovers and entries of biostratigraphic markers

Upper Triassic Shallow Water Limestones in the Sinta Ridge (Banda Sea- Indonesia)

Ten rock samples were dredged during the Banda Sea I cruise in the northern slope of the Sinta Ridge, which separates the North and South Banda basins. Some of the samples are limestones from a very shallow marine environment, with Upper Norian (to Rhaetian?) benthic Foraminifera. Similarities with eastern Sulawesi, Buru and Seram are consistent with an independant Upper Triassic block and the origin of the Banda Sea microcontinents is questionable

Land and sea study of the northeastern golfe du Lion rifted margin: the Oligocene – Miocene of southern Provence (Nerthe area, SE France)

In the western Mediterranean Sea, the Liguro-Provençal Basin (LPB) is a key area for studying passive margins because of its recent formation and abundance of onshore and offshore data. The Nerthe area located in the northern margin of LPB provides the unique continuous Oligo-Miocene deposits contemporaneous of the transition rifting to drifting. However, the age of the deposits remains debated and the link between outcrops and offshore seismic data is poorly constrained. The purpose of this paper is double. First, we intend to propose a new chronostratigraphic frame based on bio- (planktonic foraminifera, calcareous nannofossils) and magneto-stratigraphy. Second, we aim to make, through the integration of new highly time-resolved seismic data and field works, a coherent onshore-offshore link concretized by a 3D geological model. The new temporal and spatial data presented in this paper allow correlating the Oligo-Miocene sequences, defining their geometry and specifying precisely the timing of syn- and post-rift stages. The first marine transgression is now precisely dated latest Chattian within the syn-rift deposits and appears to be synchronous with the first marine deposits in the offshore wells and other marginal basins. The transition from syn-rift to post-rift appears to last 3.3 Ma at maximum, between 21.8 and 18.5 Ma (late Aquitanian to early Burdigalian). It is underlined by two major erosional unconformities bearing a hiatus of around 1 Ma. The post-rift started with a major marine transgression that is now dated from middle Burdigalian, at around 18.5 Ma, as elsewhere in the LPB. Contrarily to recent proposals, the post-rift deposits are widely represented on the northeastern margin of the "Golfe du Lion". There, the subsidence of the margin was low during the syn-rift and the transitional periods and high during the post-rift. The onset of this high post-rift subsidence appears to be synchronous with the slowdown of the Corsica-Sardinia block (CSb) motion

Early Pleistocene climate cycles in continental deposits of the Lesser Caucasus of Armenia inferred from palynology, magnetostratigraphy, and Ar-40/Ar-39 dating

Plio-Pleistocene diatomitic sequences in the Shamb paleo-lake (South Armenia, Lessee Caucasus) offer a rare opportunity to give new insights on the paleo-climate of Western Asia. We present an integrated palynological, Ar-40/Ar-39 geochronologic and magnetostratigraphic study for the most complete section in the sedimentary deposits of the Shamb paleo-lake. Ar-40/Ar-39 dating of two volcaniclastic layers provided ages of 1.24 +/- 0.03 and 1.16 +/- 0.02 Ma (2 sigma). Magnetostratigraphic data show that the entire Shamb section is of reversed polarity which, combined with Ar-40/Ar-39 dating, suggests that the entire section correlates with part of the Matuyama period (1.785-1.070 Ma). Pollen assemblages and macroremains diversity clearly show an alternation of glacial and interglacial phases. Age calibrations and accumulation rate extrapolation allow a direct correlation of climate changes with the global isotopic curve, and show that the Shamb section probably ranges from approximately 1.300 to 1.080 Ma (marine isotopic stages 40 to 31). The vegetation of the Lesser Caucasus developed in a mosaic pattern in a Pleistocene continental, mostly and climate. comparable to the present-day climate. The observed vegetation changes record a dominant climate response to the obliquity orbital parameter, but the influence of precession could not be established from the Shamb data. Pollen and macroflora both indicate that glacial periods were cold and dry and that interglacials were warm with local humidity. The Early Pleistocene climatic model for Western Asia is thus similar to the climatic model for the Mediterranean area

Ages and stratigraphical architecture of late Miocene deposits in the Lorca Basin (Betics, SE Spain): New insights for the salinity crisis in marginal basins

Unlike most Neogene basins of the Betic Cordillera where the Salinity Crisis is dated to the Messinian, a contradictory Tortonian dating was proposed for evaporites of the Lorca Basin. As a consequence, complex structural models have been proposed in the literature to explain this discrepancy in the timing of evaporites. In order to integrate the Lorca Basin into the geological context of the western Mediterranean domain during the Late Miocene, new sedimentological and stratigraphical studies coupled with new dating were performed, which allow us to propose a Messinian age for both diatomite-bearing deposits and evaporites of the Lorca Basin. These new ages challenge the idea of a Tortonian salinity crisis in the Lorca Basin. Three main events of base-level drop were evidenced during the Messinian. Each event is correlated with successive steps of basin restriction. Shallow salina evaporites were deposited after a base-level fall during the Messinian before a final base-level drop, which led to the entire exposure of the basin. This last exposure is interpreted as coeval with the deposition of first evaporites and halite in the deep Mediterranean basins. The reflooding which allowed the deposition of brackish deposits and a short-lived marine incursion occurred at the end of the Messinian. Base-level drops occurred during eustatic falls amplified by the gradual uplift of the Betic Cordillera. The exhumation of the Tercia ridge along the strike-slip Alhama de Murcia fault system during the Messinian probably favoured the gradual restriction of the basin. A discussion on correlations of main unconformities between several Neogene basins of the Betics is proposed, suggesting a similar structural evolution at the regional scale

The Indosinian orogeny: A perspective from sedimentary archives of north Vietnam

The Triassic stratigraphic framework for the Song Da and the Sam Nua basins, north Vietnam, suffers important discrepancies regarding both the depositional environments and ages of the main formations they contain. Using sedimentological analyses and dating (foraminifer biostratigraphy and U-Pb dating on detrital zircon), we provide an improved stratigraphic framework for both basins. A striking feature in the Song Da Basin, located on the southern margin of the South China Block, is the diachronous deposition, over a basal unconformity, of terrestrial and marine deposits. The sedimentary succession of the Song Da Basin points to a foreland setting during the late Early to the Middle Triassic, which contrasts with the commonly interpreted rift setting. On the northern margin of the Indochina Block, the Sam Nua basin recorded the activity of a proximal magmatic arc during the late Permian up to the Anisian. This arc resulted from the subduction of a southward dipping oceanic slab that separated the South China block from the Indochina block. During the Middle to the Late Triassic, the Song Da and Sam Nua basins underwent erosion that led to the formation of a major unconformity, resulting from the erosion of the Middle Triassic Indosinian mountain belt, built after an ongoing continental collision between the South China and the Indochina blocks. Later, during the Late Triassic, as syn- to post-orogenic foreland basins in a terrestrial setting, the Song Da and Sam Nua basins experienced the deposition of very coarse detrital material representing products of the mountain belt erosion