Early Stages Of Maturation Research Articles

Petrographic and chemical structure characteristics of amorphous organic matter in marine black shales: Insights from Pennsylvanian and Devonian black shales in the Illinois Basin

Amorphous organic matter (AOM or bituminite) is a major oil-prone liptinite maceral in black shales that can be classified into two main types: low-reflectance AOM and micrinized AOM. In this study, we investigated the petrographic and chemical structure characteristics of these two types of AOM and discussed their origin based on 15 marine black shale samples from the Illinois Basin, including 5 samples from the Pennsylvanian shales and 10 samples from the Upper Devonian New Albany Shale. The studied samples are at early mature stage, with mean vitrinite reflectance ranging from 0.64 to 0.74%. Low-reflectance AOM is the dominant organic matter (OM) in all samples and micrinized AOM is common only in the Pennsylvanian strata but is very rare in the New Albany Shale. There are significant differences in reflectance, petrographic characteristics, and chemical structure characteristics between low-reflectance and micrinized AOM. Low-reflectance AOM has a reflectance of 0.30 to 0.57%, whereas the reflectance of micrinized AOM is typically >1.0%, which makes micrinized AOM brighter than low-reflectance AOM under an optical microscope. Both types of AOM have heterogeneous texture, occur as structureless organic streaks or lenses, and have abundant clay-sized mineral inclusions. Compared to micrinized AOM, low-reflectance AOM has lower aromaticity and higher aliphatic chain length (inferred from the CH2/CH3 ratio). Based on the petrographic and chemical functional groups characteristics, we proposed evolutionary pathways for the formation of low-reflectance and micrinized AOM in marine black shales during early diagenesis. AOM is originally derived from microbially degraded phytoplankton. Low-reflectance AOM formed in the fermentation zone through microbial degradation of phytoplankton by anaerobic bacteria. In comparison, micrinized AOM is a product of an advanced degree of microbial degradation of phytoplankton by aerobic bacteria that preferentially consume aliphatic functional groups over aromatics in the oxidation zone. Different depositional environments and subsequent diagenetic alterations resulted in the difference in micrinized AOM content between the New Albany Shale and Pennsylvanian shales. This study provides a better understanding of the origin, formation, and thermal maturation of dispersed AOM in black shale successions.

Identification of MKRN1 as a second E3 ligase for Eag1 potassium channels reveals regulation via differential degradation

Mutations in the human gene encoding the neuron-specific Eag1 voltage-gated K+ channel are associated with neurodevelopmental diseases, indicating an important role of Eag1 during brain development. A disease-causing Eag1 mutation is linked to decreased protein stability that involves enhanced protein degradation by the E3 ubiquitin ligase cullin 7 (CUL7). The general mechanisms governing protein homeostasis of plasma membrane- and endoplasmic reticulum (ER)-localized Eag1 K+ channels, however, remain unclear. By using yeast two-hybrid screening, we identified another E3 ubiquitin ligase, makorin ring finger protein 1 (MKRN1), as a novel binding partner primarily interacting with the carboxyl-terminal region of Eag1. MKRN1 mainly interacts with ER-localized immature core-glycosylated, as well as nascent nonglycosylated, Eag1 proteins. MKRN1 promotes polyubiquitination and ER-associated proteasomal degradation of immature Eag1 proteins. Although both CUL7 and MKRN1 contribute to ER quality control of immature core-glycosylated Eag1 proteins, MKRN1, but not CUL7, associates with and promotes degradation of nascent, nonglycosylated Eag1 proteins at the ER. In direct contrast to the role of CUL7 in regulating both ER and peripheral quality controls of Eag1, MKRN1 is exclusively responsible for the early stage of Eag1 maturation at the ER. We further demonstrated that both CUL7 and MKRN1 contribute to protein quality control of additional disease-causing Eag1 mutants associated with defective protein homeostasis. Our data suggest that the presence of this dual ubiquitination system differentially maintains Eag1 protein homeostasis and may ensure efficient removal of disease-associated misfolded Eag1 mutant channels.

감귤 활용 특허 추세 분석

Citrus fruits are native to India, Myanmar, Peninsular Malaysia, Indochina, China, Korea, and Japan. The citrus cultivation in the world spreads from the tropics(from 40 degrees north latitude to 40 degrees south latitude) to temperate zones, reaching about 50 countries. Among the ingredients of citrus peel, turpentine, rutin, and hesperedin have various effects. As a result of investigating cases of domestic and foreign patents related to citrus fruits and analyzing patent trends, domestic and foreign patent applications have been decreasing rapidly since 2017, and are mainly counted in the order of food, cosmetics, and medical substances. The distribution by country was 65% in Japan, 21% in China, and 11% in Korea. Japan is specialized in medicines, cosmetics and related machinery, while Europe is concentrated in medicines and cosmetics. In the United States, it appears that plant patents dominate. The patent trend in the field of citrus utilization in Korea appears to be in the early stages of maturity passed the development stage in the transition analysis divided into development stage, maturation stage, reflux stage, and resurrection stage.

Characterization and sensory analysis of some Tunisian date cultivars consumed at early maturity stage

ISHS XXX International Horticultural Congress IHC2018: VII International Symposium on Tropical and Subtropical Fruits, Avocado, II International Symposium on Jackfruit and Other Moraceae and II International Symposium on Date Palm Characterization and sensory analysis of some Tunisian date cultivars consumed at early maturity stage

Comparative Proteomic Analysis of Walnut (Juglans regia L.) Pellicle Tissues Reveals the Regulation of Nut Quality Attributes.

Walnuts (Juglans regia L.) are a valuable dietary source of polyphenols and lipids, with increasing worldwide consumption. California is a major producer, with ’Chandler’ and ’Tulare’ among the cultivars more widely grown. ’Chandler’ produces kernels with extra light color at a higher frequency than other cultivars, gaining preference by growers and consumers. Here we performed a deep comparative proteome analysis of kernel pellicle tissue from these two valued genotypes at three harvest maturities, detecting a total of 4937 J. regia proteins. Late and early maturity stages were compared for each cultivar, revealing many developmental responses common or specific for each cultivar. Top protein biomarkers for each developmental stage were also selected based on larger fold-change differences and lower variance among replicates, including proteins for biosynthesis of lipids and phenols, defense-related proteins and desiccation stress-related proteins. Comparison between the genotypes also revealed the common and specific protein repertoires, totaling 321 pellicle proteins with differential abundance at harvest stage. The proteomics data provides clues on antioxidant, secondary, and hormonal metabolism that could be involved in the loss of quality in the pellicles during processing for commercialization.

Preliminary investigation of the hydrocarbon generation potential from the post-rift Abbas shale Formation (Pliocene) in the Tihamah Basin, south-eastern Yemeni Red Sea

Pliocene shales included in the post-rift Abbas Formation were recovered from an exploratory well (Kathib-01) in the Tihamah Basin and geochemically analyzed. A preliminary evaluation of the organic facies of the Abbas shales and their petroleum generation potential was conducted based on basic organic geochemical results. Most Abbas shale samples had total organic carbon (TOC) contents < 1% and a fair source potential, while the remaining samples, with TOC contents > 1%, had a relatively good potential. Overall, the Rock–Eval hydrogen index values of the shales analyzed were between 96 and 234 mg of hydrocarbon per gram of TOC (mg HC/g TOC), indicating two dominant organic facies: types III and II/III kerogen, which indicate the presence of mainly gas- and oil-prone source rocks. We conclude that the Pliocene Abbas shales in the Tihamah Basin are still in a very early-mature stage (with respect to the oil window) and, hence, have not generated petroleum yet.

Calcium Bioavailability in the Soluble and Insoluble Fibers Extracted from Opuntia ficus indica at Different Maturity Stages in Growing Rats.

Childhood and adolescence are crucial stages of life for bone health. Therefore, an adequate calcium intake and a healthy life style constitute the main strategies to prevent the risk of osteoporosis-related fractures during adulthood. It has been demonstrated that inclusion of indigestible carbohydrates in foods can help improve calcium absorption in growing stages. The objective of this study was to evaluate the effect of supplementation of soluble and insoluble fibers extracted from O. ficus indica cladodes on calcium bioavailability. Male Wistar rats 4-week old were fed diets added with soluble and insoluble fibers extracted from O. ficus indica cladodes at early and late maturity stages, as the only source of calcium. The mineral content, bone mineral density (BMD), physical, microstructural, and biomechanical properties of rat femurs were determined. The bones of rats fed with diets containing a soluble fiber extracted from O. ficus indica at early and late maturity stages exhibited better bone properties (resistance to fracture, microarchitecture, and calcium content) than control rats and rats fed with an insoluble fiber from O. ficus indica cladodes at both maturity stages. As expected, based on these results, the BMD values were higher in adolescent and pubertal rats fed with a diet containing the O. ficus indica soluble fiber. These results demonstrate that the soluble fiber from O. ficus indica cladodes is indeed a valuable source of bioavailable calcium, which contributes to improve physical, densitometric, biomechanical, and microstructural properties of bone in growing rats.

MYASTHENIA & RELATED DISORDERS: P.37 Autophagy affected in patients with hypokalemic periodic paralysis

Hypokalemic periodic paralysis (hypoPP) is an autosomal dominant rare disorder that is caused by mutations in the genes for voltage gated calcium channel CaV1.1 (CACNA1S) and NaV1.4 (SCN4A). Patients with hypoPP may suffer from periodic paralysis alone, periodic paralysis with weakness or permanent weakness. HypoPP has been known to be associated with vacuolar myopathy for decades but the cause of this has not been known. We have investigated a cohort of 14 hypoPP patients with the R528H mutation in the CACNA1S gene for vacuoles and their content. The R528H mutation has previously been demonstrated to cause a Ca2+ leak through CaV1.1 into the cytoplasm, possibly causing disturbance in the calcium homeostasis. Histology and transmission electron microscopy revealed that vacuoles had a very heterogenous content of glycogen, fibrils and autophagosomes/endosomes. Further investigation demonstrated autophagosomes and endosomes were arrested in the autophagic processing pathway between the early and late stages of maturation, as well as large non-fused lysosomes. Expression analysis of proteins associated with endosomes, autophagosomes and lysosomes showed a significant decrease in levels of proteins involved in autophagy such as Rab5, Rab7, p62/SQSTM1, LC3I, Atg5 and LAMP1 in patients with hypoPP suggesting a systemic effect on the protein expression at the gene level, which decreased mRNA expression levels confirmed, possibly through a master regulator of autophagy gene expression. The findings suggest that changes in calcium homeostasis leads to disruptions in autophagic flux and abnormally large endosomes, autophagosomes and lysosomes that contribute to the vacuoles seen in patients with hypoPP.

The investigation of minor and rare Tunisian olive cultivars to enrich and diversify the olive genetic resources of the country

Extra virgin olive oil is a basic element of the Mediterranean diet which is linked to multiple health benefits. It is particularly rich in monounsaturated fatty acids, which among fat substances are the most active for the prevention of cardiovascular disorders, and poor in saturated fats, responsible for the increase in blood cholesterol levels and directly linked to pathology. The quality of an oil is strongly influenced by many factors, including the harvesting stage of olives. To ensure that the maximum benefits of flavour and health are extracted, the maturity index must be considered; in fact, very important minor compounds such as phenols, tocopherols, chlorophylls and carotenoids, but, also, the physicochemical characteristics, depend on it. In order to enrich and to diversify the olive oil production of the country, seven rare Tunisian olive cultivars were considered, Adheffou, Barouni, Boudaoud, Chemlali Chouamekh, Fougi Gtar, Zarrazi Gtar and Zarrazi Zarzis and compared to the two main cultivars, Chemlali Sfax and Chetoui. Best quality oils are produced from olives at early stages of maturity, but, some minor cultivars showed an opposite trend. In fact, the results obtained highlight that olives of Barouni and Chemlali Chouamekh cultivars, at an advanced ripening index, produced quality oils with high tocopherol and oleic acid contents. Moreover, Fougi Gtar and Zarrazi Gtar cultivar olive oils were characterized by the highest content of chlorophyll and total tocopherols. The opposite trend was observed for Barouni cultivar olive oils. Zarrazi Zarzis and Zarrazi Gtar cultivar olive oils were the richest in luteolin; Adheffou cultivar olive oils were the richest in apigenin; Boudaoud cultivar olive oils were the richest in rutin, and together with Chemlali Sfax and Chetoui cultivar, were the richest in verbascoside. Finally, Boudaoud and Chemlali Chouamekh cultivar olive oils were the most abundant in oleic acid.

Two species of Carcinonemertes Coe, 1902 (Nemertea: Carcinonemertidae) infesting the Caribbean spiny lobster, Panulirus argus (Latreille, 1804) (Decapoda: Achelata: Palinuridae), in Saint Kitts, West Indies

Abstract The Caribbean spiny lobster, Panulirus argus (Latreille, 1804), is an important resource in the Western Atlantic Ocean, Caribbean Sea, and Gulf of Mexico. A nemertean egg predator of P. argus, Carcinonemertes conanobrieniSimpson, Ambrosio &amp; Baeza, 2017, was recorded in Florida in 2017 and Colombia in 2018. This study sought to investigate the presence of C. conanobrieni in P. argus in Saint Kitts and Nevis, eastern Caribbean Sea. Nemerteans were observed in the brood masses of P. argus. Molecular techniques confirmed its presence in the P. argus population on Saint Kitts. Egg, juvenile, and adult stages of C. conanobrieni and of an undescribed Carcinonemertes sp. were found in the brood masses of 27 of 31 (87%) ovigerous P. argus. Differences in the shape of the nemertean egg masses (string versus spherical arrangement) were confirmed as two distinct species of Carcinonemertes Coe, 1902 using molecular analyses. The juvenile stage of the undescribed Carcinonemertes sp. was detected in the gills of 72 of 320 (23%) of the P. argus individuals from Saint Kitts. The prevalence of branchial nemertean infestation was not significantly different among male and female P. argus. Female lobsters with ovaries in early stages of gonadal maturation were more likely to have branchial nemerteans relative to those with ovaries in late stages of maturation, suggestive of nemertean migration from gills to egg mass once the host oviposits. This is the first report of C. conanobrieni in the Caribbean spiny lobster from the eastern Caribbean, which is approximately 1,300 miles from Florida and 1,000 miles from Colombia. This is also the first report of an undescribed nemertean worm in P. argus. The high prevalence of Carcinonemertes spp. in P. argus raises concern for the extent to which these egg predators may be impacting P. argus in Saint Kitts, an important fishery on the island.

Hydrocarbon generation from lacustrine shales with retained oil during thermal maturation

Thermal maturation in the shale oil/gas system is inherently complex due to the competitive interplays between hydrocarbon generation and retention processes. To study hydrocarbon generation characteristics from shales within different stages of thermal maturation under the influence of retained oil, we performed Micro-Scale Sealed Vessels (MSSV) pyrolysis on a set of artificially matured lacustrine shale samples from the Shahejie Formation in the Dongpu Depression in Bohai Bay Basin, China. Experimental results show that hydrocarbon yields of shale samples with or without retained oil at various thermal maturities follow different evolution paths. Heavy components (C15+) in samples crack at high temperatures and generally follow a sequence, where they first transform into C6–14 then to C2–5 and C1. Methane accounts for most of the gaseous products at high temperatures in all samples, with different origins. The cracking of C2–5 is the main methane-generating process in samples with retained oil, whereas the source of methane in samples without retained oil is kerogen. In the studied shales, retained oils at early-mature stage retard the transformation of liquid to gaseous hydrocarbon and prompt the cracking of C2–5 to C1 to some extent. TSR reaction related to gypsum in the studied samples is the primary reason that can explain the loss of hydrocarbon yields, especially at high temperatures. In addition, transformation of volatile hydrocarbons to gas and coke also accounts for the loss of generated hydrocarbon, as a secondary factor.

Impacts of community market development on the residents’ well-being and satisfaction

Purpose This study aims to investigate the attitude and effects that community residents perceive the development of community market as a tourist attraction. The study examines the moderating role of the stages of the community life cycle, particularly the consolidation and stagnation stages, on the perceived tourism impacts concerning the community well-being. Design/methodology/approach Structural equation modelling using partial least squares analysis has been used in this study. This study has collected the responses from 852 respondents who are the residents of the 10 community markets in Thailand. Findings The key findings reveal that under the context of community markets, the economic factor, cultural factor and attitude of residents towards community market development have strong influences on community well-being, while the environmental factor does not show influence. Moreover, a deeper investigation on the stages of community development reveals various emphases on their impacts on the community well-being. The residents of the markets under the consolidation (early maturity) stage perceive the economic and cultural impacts to have more influence on well-being than the other stages, whereas residents of the markets under the stagnation (late maturity) stage perceive that the environmental factor and the attitude of having the community market have more influence. Although the findings that use the community life cycle as a moderating role do not yield significant results, they provide a preliminary understanding of how tourism stages shape the perception of residents on community well-being. Originality/value The findings provide insights into one type of domestic tourism, the community market, which is a common tourist attraction in Thailand. Community markets have not been particularly investigated in previous literature. This study is also among a handful works which apply the tourism life cycle as a moderating role to investigate the perception of residents towards the economic, cultural and environmental impacts on community well-being.

Proliferative activity is disturbed in myeloproliferative neoplasms (MPN), myelodysplastic syndrome (MDS), and MDS/MPN diseases. Differences between MDS and MDS/MPN.

The proliferation marker Ki‐67 is widely used within the field of diagnostic histopathology as a prognostic marker for solid cancers. However, Ki‐67 is hardly used for prognostic and diagnostic purposes in flow cytometric analyses of hematologic neoplasms. In the present study, we investigated to what extent the proliferative activity, as determined by Ki‐67 expression, is disturbed in myeloproliferative neoplasms (MPN), myelodysplastic syndrome (MDS), and MDS/MPN diseases. Bone marrow aspirates from 74 patients suffering from MPN, MDS, or MDS/MPN, and aspirates from 50 non‐malignant cases were analyzed by flow cytometry for Ki‐67 expression in the erythro‐, myelo‐, and monopoiesis. Ki‐67 expression was used to investigate the proliferative activity during the various maturation steps within these hematopoietic cell lineages. In the MPN patient cohort, the proliferative activity of all cell lineages is significantly higher during almost all maturation stages compared to those of the benign control cohort. In the MDS and MDS/MPN cohort, a significantly lower proliferative activity is observed in the early maturation stages. In the MDS/MPN patient cohort, increased proliferative activity is seen in the later stages of the maturation. MDS and MDS/MPN display a distinct pattern in the proliferating fraction of maturing hematopoietic cells. This could become of added value in order to classify these malignancies based on their biological background and behavior, as well as in gaining a better understanding into the pathobiology of these malignancies.

Seed Dormancy Breaking and Germination in Bituminaria basaltica and B. bituminosa (Fabaceae)

Most legumes are well-known for the physical dormancy of their seeds; hence, the implementation of appropriate scarification techniques is essential for introducing new legume crops within agricultural systems. This study investigated morpho-anatomical traits and dormancy-breaking requirements in two taxa of the genus Bituminaria: the widespread B. bituminosa and the point endemic B. basaltica. As the species under investigation show monospermic indehiscent legumes, pods were used in this research. We performed pod trait measurements, light microscopy observations on the seed coat anatomical structure, and germination tests after mechanical, thermal, and chemical scarification treatments for seed dormancy breaking. Moreover, germination performance at different pod maturity stages and storage times was tested. Differences in morpho-anatomical traits were found, with B. basaltica having a thicker palisade cell layer and B. bituminosa showing larger pods. All of the scarification treatments proved to be able to break physical dormancy, with mechanical and chemical scarification being the most effective methods in both species. Nevertheless, dormancy-breaking treatments performed better in B. bituminosa. Seeds at early pod maturity stages showed higher germination capacity in both species. Overall, this research provided background knowledge on seed collection time, storage strategy, and effective pre-sowing treatment, which might contribute to enhance propagation and use of Bituminaria species for multiple purposes. Under this perspective, the future characterization of additional Bituminaria genetic resources from other Mediterranean populations will have remarkable importance.

Immature Immunoglobulin Gene Rearrangements Are Recurrent in B Precursor Adult Acute Lymphoblastic Leukemia Carrying TP53 Molecular Alterations.

Here, we describe the immunoglobulin and T cell receptor (Ig/TCR) molecular rearrangements identified as a leukemic clone hallmark for minimal residual disease assessment in relation to TP53 mutational status in 171 Ph-negative Acute Lymphoblastic Leukemia (ALL) adult patients at diagnosis. The presence of a TP53 alterations, which represents a marker of poor prognosis, was strictly correlated with an immature DH/JH rearrangement of the immunoglobulin receptor (p < 0.0001). Furthermore, TP53-mutated patients were classified as pro-B ALL more frequently than their wild-type counterpart (46% vs. 25%, p = 0.05). Although the reasons for the co-presence of immature Ig rearrangements and TP53 mutation need to be clarified, this can suggest that the alteration in TP53 is acquired at an early stage of B-cell maturation or even at the level of pre-leukemic transformation.

Soil erosion and flood hazard zonation using morphometric and morphotectonic parameters in Upper Alaknanda river basin

In the present study, detailed morphometric, morphotectonic, statistical and hazard analyses have been carried out in the Upper Alaknanda river basin (UAB) located in Central Himalayas, Garhwal, India. The study area is bounded by the South Tibetan Detachment System in the north and by the Main Central Thrust in the south. The major river flowing in the area is Alaknanda which is a major tributary of river Ganga. The purpose of this study is to examine the influence of active tectonics, flood hazard, and soil erosion on the basis of morphotectonic and morphometric parameters using the Cartosat-1 Digital Elevation Model and ArcGIS software. The study area is divided into 10 sub-basins, where 50 morphometric and 6 morphotectonic parameters were calculated. Bifurcation ratio and stream frequency show that streams up to third order is having steep gradient and rolling through highly dichotomized terrain, due to which high overland flow and less groundwater recharge takes places, whereas drainage density clearly indicates the high flood possibility in the region. Morphotectonic parameters indicate relatively young to an early mature geological stage of sub-basins and tectonically active region. The statistical analysis of morphometric parameters is carried out by using correlation analysis, hierarchal cluster analysis, and principal component analysis. Based on their susceptibility to soil erosion, morphometry and landcover classification is carried out to prioritize the sub-basins of UAB. The combined morphometric, morphotectonic and statistical analysis indicates that the area is tectonically active and highly prone to flood, flood induced landslide and soil erosion. The case study of the 2013 flash flood event at three locations Benakuli, JP HEP and Pulna also confirms that the study area is hydro-geologically active to flood and flood induced hazards. The results obtained in this study are directly related to watershed management and hence soil erosion, tectonic activities and flash flood possibilities should be taken into consideration during future development in the area.

Source Rocks Characterization Of Agbada And Akata Formations In The Niger Delta, Nigeria

The geochemical analysis was performed on twelve (12) core samples from 6 wells of different formations (Akata, Agbada, and Akata/Agbada) of the onshore Niger Delta Basin. The study was essentially based on the results of the Rock-Eval 6 Pyrolysis to evaluate organic matter abundance, quality, and thermal maturity. The Total Organic Carbon (TOC) varies between 0.6 and 3.06 wt% and the Hydrogen Index (IH) of the studied samples ranges from 38 to 202 mgHC/g TOC, indicating predominantly Type III (gas prone) and mixed type II/III (gas and oil-prone) kerogen. This suggests terrigenous and a mixture of marine and terrigenous organic matter deposited in a paralic marine setting. The organic matter is immature to early mature according to the thermal maturity parameter (414&lt;Tmax&lt;432). The well Isan 9 from Agbada (6760 ft) and Agbada/Akata (8680 ft) shows petroleum generation potential of fair (2,5 &lt; S2 &lt; 5 mg HC/g rock) to good (5 &lt; S2 &lt; 10 mgHC/g rock) and poor for the other wells. The maturation of the kerogen indicates a very early stage of maturation (Tmax= 432°C). The results indicate that the shales from Agbada and the transition zone between the upper and lower parts of the Akata Shales are more shaly and perhaps the more mature part of the Agbada formation can be the potential source rocks of Niger Delta Basin.

Insights of the pore system of lacustrine shales from immature to late mature with the aid of petrology, mineralogy and porosimetry: A case study of the Triassic Yanchang Formation of the Ordos Basin, North China

The study of pore network evolution is an important aspect of tight shale reservoir characterization. Pore spaces in shales consist of three major types: interparticle pores and intraparticle pores associated with mineral matrix and organic-matter pores. In this study, the evolution of pore networks for each pore type in lacustrine shales during thermal maturation was studied based on a suite of 19 Triassic Yanchang Formation shale samples from the Ordos Basin across a maturation gradient from immature to late mature (vitrinite reflectance (Ro) from 0.36 to 1.30%). The results show that different pore types follow systematic evolutions during thermal maturation and that the evolution of pore type and pore size is critically controlled by multiple diagenetic processes such as mechanical compaction, cementation, mineral dissolution, clay mineral transformation, and organic matter thermal maturation. Specifically, at immature and early mature stages (Ro < 0.55%), pores associated with mineral matrix are abundant and have moderate pore sizes. Interparticle pores exhibit preferential orientation along clay platelets. At the mature stage (0.55% < Ro < 1.15%), pores associated with mineral matrix have the smallest size, and interparticle pores become less common and show reduced preferential orientation because of mechanical compaction and cementation. Organic-matter pores start to develop at a maturity level of Ro 0.77% and higher. The total porosity and BET specific surface area show minimum values at Ro 1.12%, mainly because pre-existing matrix-related pores are destroyed by mechanical compaction and filled by migrated bitumen and liquid hydrocarbons, and then they increase when Ro exceeds 1.12%, which likely results from the development of secondary organic-matter nanopores due to the generation and expulsion of gaseous hydrocarbons. An increase in pore size of matrix-related pores at the late mature stage (1.15% < Ro < 1.30%) could be a result of dissolution by organic acid generated during organic matter thermal maturation.

Geochemical significance of tricyclic and tetracyclic terpanes in source rock extracts from the Offshore Niger Delta Basin, Nigeria

Tricyclic and tetracyclic terpanes are important constituents of crude oil and source rock extracts. However, they have not been reported in the Offshore Niger Delta Basin, Nigeria. Thus, the present study investigated the geochemical significance of tricyclic and tetracyclic terpanes in source rock extracts from the Offshore Niger Delta Bain, Nigeria with gas chromatography-mass spectrometry (GC-MS). The total relative abundances of tricyclic terpanes, C19TT–C21TT, and C23TT in the rock samples ranged from 82.50 to 96.37%, 50.08 to 74.17%, and 25.83 to 49.92%, respectively. These values showed the source rocks were formed from a mixed origin (terrestrial and marine). Among the tricyclic and tetracyclic terpanes identified in the rock extracts, the conventional (C20TT, C23TT, C24TT, C24TeT) and recent (Y1, X1, Z1) were more prominent than all others, indicating mixed input of terrigenous and marine organic matter. The C24TT/C23TT, C24TeT/(C24TeT + C26TT), C19TT/C23TT, C20TT/C23TT, C25TT/C24TeT, C25TT/C26TT, C19TT/C20TT, C24TeT/C26TT, Z1/(Z1 + C24TT), and Y1/(Y1 + C24TT) in the rock samples range from 0.33 to 1.30, 0.76 to 0.90, 0.18 to 0.73, 0.34 to 1.05, 0.33 to 1.74, 0.30 to 1.39, 0.31 to 0.89, 1.66 to 4.33, 0.36 to 0.83, and 0.34 to 0.79, respectively. These values further showed that the rock samples were formed from mixed input of terrigenous and marine organic matter and deposited under oxic to suboxic conditions in lacustrine-fluvial/deltaic environments. Also, the C24TeT/C20–26TT, C24TeT/C30HOP, and C23TT/C30HOP ranged from 0.16 to 0.45, 0.02 to 0.42, and 0.01 to 0.48, respectively. This range of values suggests that source rocks were within immature to early mature stage. Thus, this study showed that tricyclic and tetracyclic terpanes were effective in determining the origin, depositional environments, and thermal maturity of source rocks in the Niger Delta Basin, Nigeria.

Data to estimate costs of producing grass-clover silages.

This article presents input data and procedures used to estimate costs of producing grass-clover silages under Norwegian farming conditions. Data of yield, botanical composition and forage quality of the grass crop were derived from a field experiment comparing a three-cut system, harvested at early crop maturity stages producing highly digestible forages, and a two-cut system returning higher herbage yields of medium digestibility. Secondary data on prices of specific inputs were also provided. The data presented here can be used by advisors and farmers as a decision support tool for assessing and comparing costs of different ways of producing silage. Cost estimates of home-grown forages are also needed in bio-economic evaluations of grassland production and utilization by researchers. The data presented is related to the research article entitled: “Technical and economic performance of alternative feeds in dairy and pig production” [1].