Recent sediments of the Tigris-Euphrates delta: the southern marshlands (Ahwar)

The Lower Mesopotamian fluvial plains crossed by the Tigris-Euphrates Rivers are occupied by fresh-brackish water lakes and extensive reed marshes dominated by Phragmites sp. and Typha sp. (together locally called Ahwar). The main modern allochthonous sediment sources are: the Tigris and Euphrates seasonal floodwaters, together with aeolian dust and sand driven by storms from the western deserts and northwestern areas during summer. Other contributions to the sediment budget are made by autochthonous biochemical activity, and chemical processes within the sediments. The same sources and processes were responsible for sedimentation during older periods of Holocene as reflected in the examination of several borehole sequences in Lower Mesopotamia. The surface and subsurface sediments are dominantly silty with silt comprising about 55% of the sediment mainly as clayey-silt and clayey-sandy-silt; the remainder consists of varying quantities of clayey and sandy sediments. Clay is more abundant in the lower parts of the surface cores analysed (30-80 cm in length) and in the upper pedogenic fluvial-plain sediments of the borehole sequences in addition to the brackish/marine sediments of the Holocene Hammar Formation. Well developed stratification is found only on the surface sections of the river levees and in the clayey-rich sediments of the modern lakes and marshes. The remainder of the sediments of both surface and subsurface are generally poorly stratified with some irregular stratification and considerable bioturbation, particularly in shelly horizons. Mineralogically, the sediments of the Ahwar consist of calcite, quartz, dolomite and feldspar (particularly albite) . Aragonite is present as a result of "in situ" production by macrofauna. Some authigenic dolomite and Mg-calcite are detected in specific playa and brackish/marine units which may be accompanied by other minerals such as gypsum and palygorskite clays, particularly in the evaporitic sediments. Smectite, illite, palygorskite, kaolinite and chlorite are the main clay minerals present and those are mostly detrital in origin. Palygorskite is the most interesting clay mineral present. It is both detrital and authigenic in origin. The formation of authigenic palygorskite reflects an alkaline, Mg-rich and relatively saline environment found accompanying arid climatological conditions. It is usually found associated with authigenic dolomite and gypsum. Detrital palygorskite is here reported in the suspended sediments of the Tigris-Euphrates rivers of this area for the first time. The calcium carbonate content of the Ahwar sediments varies from 20-80%. The latter high values are only found in skeletal-rich horizons of the near-surface and subsurface sediments. The inorganic geochemistry of the sediments reflects their high calcium carbonate content. The values of most of the analysed elements were within the limits of standard mudrocks except for Ni and Cr which are surprisingly high, presumably mainly due to the high contents of these elements in the suspended materials of the major rivers and of the aeolian deposits. The total organic content of the sediments is usually 5% TOC) are mainly restricted to the upper surface layers of the surface sections and at some specific depths of a few borehole sections. The latter has been proved to be an ancient Ahwar (lake/marsh) sedimentary unit. The preservation of the organic matter has mainly taken place during the mid-Holocene transgression and particularly along the depositional axis areas of the main Mesopotamian Basin. Pyrolysis, gas chromatography and petrography of the organic matter have revealed that many reed-originated biomarkers were present in the gas chromatograms which supported the conclusions from the petrographic analysis of organic matter indicating that reeds were the main source of this material in both ancient and present times. Peat is not forming at the present time in most parts of the area studied, except in some limited northwestern parts such as Lake Zechri and surrounded marshes. The examination of the fauna revealed the dominance of aragonitic molluscs of various species, in addition to some calcareous microfauna mainly as foraminifers and ostracods. The dominant species of the latter two were Ammonia beccarii and Cyperidles torosa respectively. These two species indicated the influence of the sea in the area as various brackish/marine coastal environments. Both surface and subsurface sequences have been subdivided into various sedimentary units. The units have been proved useful for regional correlation; particularly the three surface units (i.e. upper organic-rich, intermediate shelly and lower clayey brackish/marine units), while the five borehole units (i.e. modern fluvial-plain/Ahwar, older brackish/marine, ancient lake/marsh, ancient playa and ancient fluvial/gypcretes units) proved to be correlated throughout Lower Mesopotamia. These sedimentary units have been differentiated geochemically for both surface and subsurface sections using a multivariate statistical package (MVSP). The reconstruction of the Holocene geological history and the calculation of the sedimentation rates have been made using and ^^"^Cs dates of subsurface peats, near-surface shelly sediments, and the upper 20 cm of the surface sections respectively. Sea-level fluctuation during the Holocene has been the main factor in the evolution of the deltaic area with climatological changes, local neotectonics and differential sedimentation rates during Holocene might be additional factors.Open acces

Inflammatory Stratification in Primary Sjögren’s Syndrome Reveals Novel Immune Cell Alterations in Patients’ Minor Salivary Glands

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Proteomic Profiling of Saliva and Tears in Radiated Head and Neck Cancer Patients as Compared to Primary Sjögren’s Syndrome Patients

Patients with head and neck cancer (HNC) and patients with primary Sjögren’s syndrome (pSS) may exhibit similar symptoms of dry mouth and dry eyes, as a result of radiotherapy (RT) or a consequence of disease progression. To identify the proteins that may serve as promising disease biomarkers, we analysed saliva and tears from 29 radiated HNC patients and 21 healthy controls, and saliva from 14 pSS patients by mass spectrometry-based proteomics. The study revealed several upregulated, and in some instances overlapping, proteins in the two patient groups. Histone H1.4 and neutrophil collagenase were upregulated in whole saliva of both patient groups, while caspase-14, histone H4, and protein S100-A9 were upregulated in HNC saliva only. In HCN tear fluid, the most highly upregulated protein was mucin-like protein 1. These overexpressed proteins in saliva and tears play central roles in inflammation, host cell injury, activation of reactive oxygen species, and tissue repair. In conclusion, the similarities and differences in overexpressed proteins detected in saliva from HNC and pSS patients may contribute to the overall understanding of the different pathophysiological mechanisms inducing dry mouth. Thus, the recurring proteins identified could possibly serve as future promising biomarkerspublishedVersio

Cytokines Explored in Saliva and Tears from Radiated Cancer Patients Correlate with Clinical Manifestations, Influencing Important Immunoregulatory Cellular Pathways

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Stratigraphic correlation and paleoenvironmental analysis of the hydrocarbon-bearing Early Miocene Euphrates and Jeribe formations in the Zagros folded-thrust belt

The Lower Miocene Euphrates and Jeribe formations are considered as the main targets of the Tertiary petroleum system in the western part of the Zagros Basin. The formations consist of carbonates with some evaporate intercalations of the Dhiban Formation. This study utilized data from a field investigation including newly described outcrop sections and newly discovered productive oil fields within the Kirkuk embayment zone of the Zagros fold and thrust belt such as Sarqala and Kurdamir wells. This work is the first to show a stratigraphic correlation and paleoenvironmental interpretation by investigating both well data and new outcrop data. Three depositional environments were identified, (1) an inner and outer ramp belts environment, (2) shoal environment, and (3) restricted lagoon environment. Within these 3 environments, 12 microfacies were identified, based on the distribution of fauna mainly benthonic foraminifera, rock textures, and sedimentary structures. The inferred shallow water depths and variable salinities in both the Euphrates Formation and Jeribe Formation carbonates are consistent with deposition on the inner ramp (restricted lagoon and shoal) environments. Those found in the Euphrates Formation constrained the depositional environment to the restricted lagoon and shoal environment, while the microfacies in the Jeribe Formation provided evidence for an inner ramp and middle to outer ramp belt environments. This study represents the first detailed research that focuses on the stratigraphic correlation and changes in carbonate facies with the main aim to provide a wider understanding of stratigraphy of these carbonate reservoirs throughout the northern part of Iraq

Terrigenous plant wax inputs to the Arabian Sea : implications for the reconstruction of winds associated with the Indian Monsoon

Author Posting. © The Authors, 2005. This is the author's version of the work. It is posted here by permission of Elsevier B. V. for personal use, not for redistribution. The definitive version was published in Geochimica et Cosmochimica Acta 69 (2005): 2547-2558, doi:10.1016/j.gca.2005.01.001.We have determined the accumulation rates and carbon isotopic compositions (δ13C) of long-chain (C24–C32) terrigenous plant wax fatty acids in 19 surface sediment samples geographically distributed throughout the Arabian Sea in order to assess the relationship between plant wax inputs and the surrounding monsoon wind systems. Both the accumulation rate data and the δ13C data show that there are three primary eolian sources of plant waxes to the Arabian Sea: Africa, Asia, and the Arabian Peninsula. These sources correspond to the three major wind systems in this region: the summer (Southwest) monsoon, the winter (Northeast) monsoon, and the summer northwesterlies that blow over the Arabian Peninsula. In addition, plant waxes are fluvially supplied to the Gulf of Oman and the Eastern African margin by nearby rivers. Plant wax δ13C values reflect the vegetation types of the continental source regions. Greater than 75% of the waxes from Africa and Asia are derived from C4 plants. Waxes delivered by northwesterly winds reflect a greater influence (25–40%) of C3 vegetation, likely derived from the Mesopotamian region. These data agree well with previously published studies of eolian dust deposition, particularly of dolomite derived from the Arabian Peninsula and the Mesopotamian region, in surface sediments of the Arabian Sea. The west-to-east gradient of plant wax δ13C and dolomite accumulation rates are separately useful indicators of the relationship between the northwesterly winds and the winds of the Southwest monsoon. Combined, however, these two proxies could provide a powerful tool for the reconstruction of both southwest monsoon strength as well as Mesopotamian aridity.This work was supported by a SGER grant from the National Science Foundation to D.O. and a Schlanger Ocean Drilling Fellowship to K.D

The genomes of two key bumblebee species with primitive eusocial organization

Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

Thermal modelling of gas generation and retention in the Jurassic organic-rich intervals in the Darquain field, Abadan Plain, SW Iran

The petroleum system with Jurassic source rocks is an important part of the hydrocarbons discovered in the Middle East. Limited studies have been done on the Jurassic intervals in the 26,500 km2 Abadan Plain in south-west Iran, mainly due to the deep burial and a limited number of wells that reach the basal Jurassic successions. The goal of this study was to evaluate the Jurassic organic-rich intervals and shale gas play in the Darquain field using organic geochemistry, organic petrography, biomarker analysis, and basin modelling methods. This study showed that organic-rich zones present in the Jurassic intervals of Darquain field could be sources of conventional and unconventional gas reserves. The organic matter content of samples from the organic-rich zones corresponds to medium-to-high-sulphur kerogen Type II-S marine origin. The biomarker characteristics of organic-rich zones indicate carbonate source rocks that contain marine organic matter. The biomarker results also suggest a marine environment with reducing conditions for the source rocks. The constructed thermal model for four pseudo-wells indicates that, in the kitchen area of the Jurassic gas reserve, methane has been generated in the Sargelu and Neyriz source rocks from Early Cretaceous to recent times and the transformation ratio of organic matter is more than 97%. These organic-rich zones with high initial total organic carbon (TOC) are in the gas maturity stage [1.5–2.2% vitrinite reflectance in oil (Ro)] and could be good unconventional gas reserves and gas source rocks. The model also indicates that there is a huge quantity of retained gas within the Jurassic organic-rich intervals

Complement C4 Copy Number Variation is Linked to SSA/Ro and SSB/La Autoantibodies in Systemic Inflammatory Autoimmune Diseases

Objective Copy number variation of the C4 complement components, C4A and C4B, has been associated with systemic inflammatory autoimmune diseases. This study was undertaken to investigate whether C4 copy number variation is connected to the autoimmune repertoire in systemic lupus erythematosus (SLE), primary Sjögren's syndrome (SS), or myositis. Methods Using targeted DNA sequencing, we determined the copy number and genetic variants of C4 in 2,290 well-characterized Scandinavian patients with SLE, primary SS, or myositis and 1,251 healthy controls. Results A prominent relationship was observed between C4A copy number and the presence of SSA/SSB autoantibodies, which was shared between the 3 diseases. The strongest association was detected in patients with autoantibodies against both SSA and SSB and 0 C4A copies when compared to healthy controls (odds ratio [OR] 18.0 [95% confidence interval (95% CI) 10.2–33.3]), whereas a weaker association was seen in patients without SSA/SSB autoantibodies (OR 3.1 [95% CI 1.7–5.5]). The copy number of C4 correlated positively with C4 plasma levels. Further, a common loss-of-function variant in C4A leading to reduced plasma C4 was more prevalent in SLE patients with a low copy number of C4A. Functionally, we showed that absence of C4A reduced the individuals’ capacity to deposit C4b on immune complexes. Conclusion We show that a low C4A copy number is more strongly associated with the autoantibody repertoire than with the clinically defined disease entities. These findings may have implications for understanding the etiopathogenetic mechanisms of systemic inflammatory autoimmune diseases and for patient stratification when taking the genetic profile into account.publishedVersio