Oil families and petroleum geochemistry of the western part of the Sirt Basin Libya

PhD ThesisThis thesis describes a detailed geochemical evaluation of the hydrocarbon potential of source rocks and the origins of the crude oils in the western and central parts of the Sirt Basin in Libya. The Sirt Basin is one of North Africa's richest and most prolific oil-bearing basins, with most of the oil being considered to be derived from the Campanian Sirte Shale and other local source rocks such as Rachmat, Etel and Hagfa Shale formations. The primary aims of this research were to determine the main source rocks that generated petroleum, determine the number of genetically distinct oil families in the basin and compare them with their parent source rocks, and to assess the regional migration and the filling directions of the reservoirs, since this information can exert a profound influence on current and future exploration activities across the study area. A study was undertaken on these source rocks and crude oils using 269 rock cuttings and 51 crude oil samples from several boreholes and oilfields in the Sirt Basin. Routine geochemical analysis in addition to biomarker analysis by gas chromatography-mass spectrometry, compound specific carbon isotopic analysis on n-alkanes and diamondoid analyse were carried out on selected source rock samples and on all of the crude oil samples. The geochemical results demonstrated the presence of various organic-rich zones within the Upper Cretaceous Sirte Shale and Rachmat source rocks. The Sirte Shale Formation is considered to have variable fair, good to very good source potential, and has good hydrocarbon generation in the study area. The Rachmat Formation shale is considered as the second potential source rock in the basin. Vitrinite reflectance, Spore Colour Index, and pyrolysis Tmax data indicate that the Upper Cretaceous shale samples are early to mid-mature in the west of the basin, and middle to late mature in the north central of the basin. Optical analysis of palynofacies slides showed that structureless, amorphous organic matter is dominant, along with the presence of some phytoclasts and reveals moderate to well preserved, fluorescent Type II marine kerogen and Type II-III kerogen. A number of biomarker and other organic facies and maturity indicating molecular marker parameters, as well as isotopic data, show that the crude oils in the western and v central parts of the Sirt Basin are genetically related and only minor variations are present between them, likely due to minor organic facies variations in the Sirt Shale and Rachmat source rocks. The biomarker parameters show dissimilarities between the crude oils in eastern part relative to the western and central part of the basin, due to variations in the organic facies and depositional environments setting of the source rocks or due to higher maturity. Based on molecular marker characteristics, oil-oil correlation identified nine oil families, plus two subfamilies in the study area: Oils from families 1A, 1B, 2, 3 and 4 are situated in the western and central parts of the Sirt Basin, while oil families 5, 6, 7, 8 and 9 are located in the eastern part of the basin. Crude oils of families 1A, 1B, 2, and 3 were interpreted as having been generated from a suboxic to anoxic marine, clay-rich and early to middle maturity source rock. Molecular and other compositional variation between oil families were attributed to organic facies and subtle maturation variations. Age-related biomarker parameters in the oils suggested that their source was Upper Cretaceous. Migration of the generated and expelled oil and gas from the Sirte Shale and Rachmat source rocks to the reservoirs of the Upper Cretaceous-Tertiary petroleum system was interpreted to have occurred along both vertical and lateral pathways along the faults, in the Oligocene to Miocene, while oil carbazole data indicated that this migration was generally likely to have been over relatively short distances.Libyan petroleum Institut

Changes in composition of colostrum of Egyptian buffaloes and Holstein cows

<p>Abstract</p> <p>Background</p> <p>Changes in colostrum composition of Egyptian buffaloes and Holstein cows collected at calving, 6, 12, 24, 48, 72, 96, 120 h and after 14 days of parturition were studied. Total solids, total protein, whey proteins, fat, lactose and ash contents were determined. Macro- and micro-elements, IgG, IgM, IGF-1, lactoferrin and vitamins (A and E) were also estimated.</p> <p>Results</p> <p>At calving, the total protein and whey proteins concentration did not differ between buffalo and cow colostrum, while total solids, fat, lactose and ash concentrations were higher in buffalo than in cow colostrum. All components decreased gradually as the transition period advanced except lactose which conversely increased. On the fifth day post-partum, concentration of total protein, whey proteins, fat, ash and total solids decreased by 69.39, 91.53, 36.91, 45.58 and 43.85% for buffalo and by 75.99, 94.12, 53.36, 33.59 and 52.26% for cow colostrum. However, lactose concentration increased by 42.45% for buffalo and 57.39% for cow colostrum. The macro-and micro-elements concentration of both colostrums tended to decline slightly toward normality on the fifth day of parturition. Buffalo colostrum had a higher concentration of vitamin E than cow colostrum during the experimental period. At calving, the concentration of vitamin A in buffalo colostrum was found to be approximately 1.50 times lower than in cow colostrum. The concentrations of IgG, IgM, IGF-1 and lactoferrin decreased by 97.90, 97.50, 96.25 and 96.70% for buffalo and 76.96, 74.92, 76.00 and 77.44% for cow colostrum, respectively after five days of parturition.</p> <p>Conclusions</p> <p>There is a dramatic change in buffalo and cow colostrum composition from the first milking until the fifth day of parturition. There are differences between buffalo and cow colostrum composition during the five days after calving. The composition of both colostrums approaches to those of normal milk within five days after parturition.</p

Information retrieval and text mining technologies for chemistry

Efficient access to chemical information contained in scientific literature, patents, technical reports, or the web is a pressing need shared by researchers and patent attorneys from different chemical disciplines. Retrieval of important chemical information in most cases starts with finding relevant documents for a particular chemical compound or family. Targeted retrieval of chemical documents is closely connected to the automatic recognition of chemical entities in the text, which commonly involves the extraction of the entire list of chemicals mentioned in a document, including any associated information. In this Review, we provide a comprehensive and in-depth description of fundamental concepts, technical implementations, and current technologies for meeting these information demands. A strong focus is placed on community challenges addressing systems performance, more particularly CHEMDNER and CHEMDNER patents tasks of BioCreative IV and V, respectively. Considering the growing interest in the construction of automatically annotated chemical knowledge bases that integrate chemical information and biological data, cheminformatics approaches for mapping the extracted chemical names into chemical structures and their subsequent annotation together with text mining applications for linking chemistry with biological information are also presented. Finally, future trends and current challenges are highlighted as a roadmap proposal for research in this emerging field.A.V. and M.K. acknowledge funding from the European Community’s Horizon 2020 Program (project reference: 654021 - OpenMinted). M.K. additionally acknowledges the Encomienda MINETAD-CNIO as part of the Plan for the Advancement of Language Technology. O.R. and J.O. thank the Foundation for Applied Medical Research (FIMA), University of Navarra (Pamplona, Spain). This work was partially funded by Consellería de Cultura, Educación e Ordenación Universitaria (Xunta de Galicia), and FEDER (European Union), and the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684). We thank Iñigo Garciá -Yoldi for useful feedback and discussions during the preparation of the manuscript.info:eu-repo/semantics/publishedVersio

The CHEMDNER corpus of chemicals and drugs and its annotation principles

The automatic extraction of chemical information from text requires the recognition of chemical entity mentions as one of its key steps. When developing supervised named entity recognition (NER) systems, the availability of a large, manually annotated text corpus is desirable. Furthermore, large corpora permit the robust evaluation and comparison of different approaches that detect chemicals in documents. We present the CHEMDNER corpus, a collection of 10,000 PubMed abstracts that contain a total of 84,355 chemical entity mentions labeled manually by expert chemistry literature curators, following annotation guidelines specifically defined for this task. The abstracts of the CHEMDNER corpus were selected to be representative for all major chemical disciplines. Each of the chemical entity mentions was manually labeled according to its structure-associated chemical entity mention (SACEM) class: abbreviation, family, formula, identifier, multiple, systematic and trivial. The difficulty and consistency of tagging chemicals in text was measured using an agreement study between annotators, obtaining a percentage agreement of 91. For a subset of the CHEMDNER corpus (the test set of 3,000 abstracts) we provide not only the Gold Standard manual annotations, but also mentions automatically detected by the 26 teams that participated in the BioCreative IV CHEMDNER chemical mention recognition task. In addition, we release the CHEMDNER silver standard corpus of automatically extracted mentions from 17,000 randomly selected PubMed abstracts. A version of the CHEMDNER corpus in the BioC format has been generated as well. We propose a standard for required minimum information about entity annotations for the construction of domain specific corpora on chemical and drug entities. The CHEMDNER corpus and annotation guidelines are available at: http://www.biocreative.org/resources/biocreative-iv/chemdner-corpus

Mechanism of GABA involvement in post-traumatic trigeminal neuropathic pain: Activation of neuronal circuitry composed of PKCγ interneurons and pERK1/2 expressing neurons

International audienc

Nigrostriatal dopaminergic depletion produces orofacial static mechanical allodynia

International audienc