Gradient Of Maturation Research Articles

Nanoscale Molecular Composition of Solid Bitumen from the Eagle Ford Group across a Natural Thermal Maturity Gradient

Microscopic solid bitumen is a petrographically defined secondary organic matter residue produced during petroleum generation and subsequent oil transformation. The presence of solid bitumen impact...

A Multi-Omics Analysis Suggests Links Between the Differentiated Surface Metabolome and Epiphytic Microbiota Along the Thallus of a Mediterranean Seaweed Holobiont.

Marine macroalgae constitute an important living resource in marine ecosystems and complex ecological interactions occur at their surfaces with microbial communities. In this context, the present study aimed to investigate how the surface metabolome of the algal holobiont Taonia atomaria could drive epiphytic microbiota variations at the thallus scale. First, a clear discrimination was observed between algal surface, planktonic and rocky prokaryotic communities. These data strengthened the hypothesis of an active role of the algal host in the selection of epiphytic communities. Moreover, significant higher epibacterial density and α-diversity were found at the basal algal parts compared to the apical ones, suggesting a maturation gradient of the community along the thallus. In parallel, a multiplatform mass spectrometry-based metabolomics study, using molecular networking to annotate relevant metabolites, highlighted a clear chemical differentiation at the algal surface along the thallus with similar clustering as for microbial communities. In that respect, higher amounts of sesquiterpenes, phosphatidylcholines (PCs), and diacylglycerylhydroxymethyl-N,N,N-trimethyl-β-alanines (DGTAs) were observed at the apical regions while dimethylsulfoniopropionate (DMSP) and carotenoids were predominantly found at the basal parts of the thalli. A weighted UniFrac distance-based redundancy analysis linking the metabolomics and metabarcoding datasets indicated that these surface compounds, presumably of algal origin, may drive the zonal variability of the epibacterial communities. As only few studies were focused on microbiota and metabolome variation along a single algal thallus, these results improved our understanding about seaweed holobionts. Through this multi-omics approach at the thallus scale, we suggested a plausible scenario where the chemical production at the surface of T. atomaria, mainly induced by the algal physiology, could explain the specificity and the variations of the surface microbiota along the thallus.

The environmental impact from an offshore windfarm: Challenge and evaluation methodology based on an ecosystem approach

Responding to pressure to combat climate change by cutting greenhouse gasses emission, Offshore Wind Farm (OWF) is currently the most developed of all the renewable energy options that are based in the marine environment. However, despite its perceived benefits, OWF construction will also lead to direct and indirect impacts on the ecosystem. Nonetheless, surprisingly few studies have sought to combine trophic web modelling tools with the framework of OWF impact assessment. The objective of this study was to develop a holistic and integrated ecosystem approach as a complementary methodology to the traditional OWF environmental impact assessment. To that end, trophic web models coupled with Ecological Network Analysis indices were used to study the structure and functioning of three sedimentary types (sandy gravel, gravelly sand, and medium sand), identified on the proposed site for a new offshore wind farm at Dieppe-Le Tréport (Normandy coast). The results from this study demonstrated that the trophic structures are strongly linked to the sedimentary types. The results also highlighted the existence of a maturity gradient moving between the three types of sediment identified. This study underlined the challenge and the need to have detailed biomass data on a maximum of biological compartments to enable an effective OWF impact assessment. We strongly consider that our approach will provide useful and practical information for environmental decision-makers and stakeholders. The same approach can be applied to other new OWF constructions in European or international waters.

Thermal maturity and reservoir quality of the Velkerri Formation, Beetaloo Sub-basin, Northern Territory

The Proterozoic (~1.43 Ga) Velkerri Formation (McArthur Basin, Northern Territory) is believed to host one of the world’s oldest petroleum systems. Drilling and production tests demonstrated the encouraging potential of this unconventional gas resource and current efforts are aimed at better defining the extent of the gas and liquid-rich portions of this shale play. In this context, we conducted a comprehensive characterisation of specimens from the Amungee Member of the Velkerri Formation (previously referred to as the Middle Velkerri) sampled along a thermal maturity gradient from wells drilled across the Beetaloo Sub-basin. The scope of our analysis was to shed light on how the organic matter in the Velkerri Formation is affected by thermal maturity and how this affects the pore structure of the host rock. To this end, we integrated light and electron microscopy imaging with Raman spectroscopy and pyrolysis techniques to define the maturity of the sediments and visualise the shale pore network. In concert with the direct imaging, bulk samples were experimentally tested to measure their gas permeability and gas adsorption capacity. The results indicate that porosity is mostly organic-hosted with pore size dominated by meso- and micro-pores (i.e. <50 nm). Methane adsorption isotherms measured at temperatures up to 80°C also show that organic content is one of the main factors controlling the amount of adsorbed gas in the Velkerri shale.

The measurement of ecosystem development in Caribbean coral reefs through topological indices

Abstract The exploration of gradients of development stages of coral reef ecosystems is a subject poorly studied, especially when they exhibit multiple degrees of geomorphological or structural development or both. The objective of the present work was to study the gradient of functional and structural maturity of the Mexican Caribbean coral reefs (CM). Here we analyzed three geomorphological zones that cover a gradient of 400 km in length in order to obtain coral reefs with different geomorphologies. Thirteen reefs were selected, for which 12 ecosystem development attributes and five topological indices were analyzed. The development attributes of coral reefs were estimated from trophic models constructed using Ecopath with Ecosim (EwE), while the topological indices were calculated from the predator-prey matrix obtained from each EwE model. Through a partial redundancy analysis (RDA) seven of the 12 development attributes (ascendency, overhead, development capacity, net primary production, ascendency/development capacity, overhead/development capacity and richness of functional group) were selected due their low or null collinearity. Using the developmental attributes selected in a non-metric multidimensional scaling (stress: 0.1) and analysis of similarities (r global: 0.828 and p: 0.001), we found a gradient of maturity that increases from north to south, i.e., northern coral reefs (e.g. Puerto Morelos) are less mature than southern coral reefs (e.g. Mahahual). On other hand, through a non-parametric ANOVA and a partial redundancy analysis (first axis: F-ratio = 62.054, p = 0.012; second axis: F-ratio = 1.591, p = 0.014; 100% of the total variance explained by the first two canonical axes) we detected that topological indices respond to development stages, in this way the control flow increases with the maturity while the intermediation, number of connections and number of interactions depredator-prey are inverse to maturity; therefore, topological indices can be used to describe development stages. The determination of a gradient of maturity in MC coral reefs should be considered in management and conservation policies, therefore different strategies must be implemented in ecosystems, because resilience and ecosystem response depend on them.

Division of diagenesis and pore evolution of a Permian Shanxi shale in the Ordos Basin, China

This research analyzed the pore evolution and diagenesis in a Permian Shanxi shale from the Ordos Basin. Thermal simulation method simulated the thermal evolution of organic matter in a sample from mature (Ro = 0.96%) to overmature (Ro = 3.05%). Gas adsorption and mercury intrusion capillary pressure techniques were used to analyze pore-size distribution across a maturation gradient. X-ray diffraction, Focused Ion Beam-Scanning Electron Microscopy and rock pyrolysis techniques were used to divide the stages of diagenesis and pore evolution. Results showed that mesopores and macropores dominate pore volume while micropores and mesopores dominate surface area. Pore volume and surface area initially decreased and then increased with maturity. Kaolinite is converted to illite and illite-smectite mixedlayer in the middle to late diagenesis stage. Pore evolution and diagenesis can be divided into four stages in a sample from mature to overmature. Factors influencing pore-size distribution are different in four stages.

Distribution of Some Diamondoids in Crude Oils from Niger Delta Basin

Some Niger Delta oils were studied for the presence of diamondoids in the oils. Oils were obtained from a well each from their respective oil fields. The objectives of the study include identification of diamondoids in the oils, use of parametric ratios to delineate biodegradation and maturity of the oils. The m/z 136 show the presence of Adamantane and the m/z135 showed the presence of 1-Methyladamantane, 2–Methyladamantane, 1–Ethyladamantane and 2-Ethyladamantanein the oils. The nC17/Pr and nC17+nC18/(Pr+Ph) showed good biodegradation trend for the oils. 1MA/nC11 and nC17+nC18/(Pr+Ph plot did not show a good biodegradation gradient though of similar trend. 1MA/ nC11 showed a restricted spread. The plot 1MA/nC11 and 1MA+2MA/A showed a better spread for 1MA+2MA/A. The1MA/1MA+2MA (Methyladamantane index) showed a better maturity gradient and is good for the Nigerian oils but the 1EA/1EA+2EA (Ethyladamantane index) showed restricted spread for a good maturity gradient and may be better for higher matured oils than the Niger delta Oils.

Characterization and range of kerogen properties in the Vaca Muerta Formation, Neuquén Basin, Argentina

The Vaca Muerta Formation of the Neuquén Basin, Argentina, is a prolific oil- and gas-producing resource, characterized by high organic content and a large thermal maturity gradient running east to west. Kerogen properties are expected to vary substantially across the basin because of the range in thermal maturity (immature to dry gas). A comprehensive dataset of kerogen properties comprising thermal maturity, elemental composition, skeletal density, and specific surface area was acquired on cores from six wells. Kerogen isolates were prepared using a novel combination of acid demineralization and critical point drying that preserves the chemical and microstructural characteristics of kerogen. Kerogen properties are found to differ substantially between the studied wells, with variations correlating with thermal maturity. Kerogens show decreasing hydrogen content (H/C ratio ∼0.9–0.4) and nuclear hydrogen index (∼0.75–0.45), increasing grain density (∼1.28–1.55 g/cm3), and increasing surface area (∼100–350 m2/g) during maturation. These properties can dominate the response of logging tools run in organic-rich mudrocks and are needed to properly interpret downhole logs run therein for appraisal of porosity, hydrocarbon volumes, and total hydrocarbon-in-place, for example.

Sublaminar organization of the human subplate: developmental changes in the distribution of neurons, glia, growing axons and extracellular matrix.

The objective of this paper was to collect normative data essential for analyzing the subplate (SP) role in pathogenesis of developmental disorders, characterized by abnormal circuitry, such as hypoxic-ischemic lesions, autism and schizophrenia. The main cytological features of the SP, such as low cell density, early differentiation of neurons and glia, plexiform arrangement of axons and dendrites, presence of synapses and a large amount of extracellular matrix (ECM) distinguish this compartment from the cell-dense cortical plate (CP; towards pia) and large fiber bundles of external axonal strata of fetal white matter (towards ventricle). For SP delineation from these adjacent layers based on combined cytological criteria, we analyzed the sublaminar distribution of different microstructural elements and the associated maturational gradients throughout development, using immunocytochemical and histological techniques on postmortem brain material (Zagreb Neuroembryological Collection). The analysis revealed that the SP compartment of the lateral neocortex shows changes in laminar organization throughout fetal development: the monolayer in the early fetal period (presubplate) undergoes dramatic bilaminar transformation between 13 and 15 postconceptional weeks (PCW), followed by subtle sublamination in three 'floors' (deep, intermediate, superficial) of midgestation (15-21 PCW). During the stationary phase (22-28 PCW), SP persists as a trilaminar compartment, gradually losing its sublaminar organization towards the end of gestation and remains as a single layer of SP remnant in the newborn brain. Based on these sublaminar transformations, we have documented developmental changes in the distribution, maturational gradients and expression of molecular markers in SP synapses, transitional forms of astroglia, neurons and ECM, which occur concomitantly with the ingrowth of thalamo-cortical, basal forebrain and cortico-cortical axons in a deep to superficial fashion. The deep SP is the zone of ingrowing axons - 'entrance (ingrowth) zone'. The process of axonal ingrowth begins with thalamo-cortical fibers and basal forebrain afferents, indicating an oblique geometry. During the later fetal period, deep SP receives long cortico-cortical axons exhibiting a tangential geometry. Intermediate SP ('proper') is the navigation and 'nexus' sublamina consisting of a plexiform arrangement of cellular elements providing guidance and substrate for axonal growth, and also containing transient connectivity of dendrites and axons in a tangential plane without radial boundaries immersed in an ECM-rich continuum. Superficial SP is the axonal accumulation ('waiting compartment') and target selection zone, indicating a dense distribution of synaptic markers, accumulation of thalamo-cortical axons (around 20 PCW), overlapping with dendrites from layer VI neurons. In the late preterm brain period, superficial SP contains a chondroitin sulfate non-immunoreactive band. The developmental dynamics for the distribution of neuronal, glial and ECM markers comply with sequential ingrowth of afferents in three levels of SP: ECM and synaptic markers shift from deep to superficial SP, with transient forms of glia following this arrangement, and calretinin neurons are concentrated in the SP during the formation phase. These results indicate developmental and morphogenetic roles in the SP cellular (transient glia, neurons and synapses) and ECM framework, enabling the spatial accommodation, navigation and establishment of numerous connections of cortical pathways in the expanded human brain. The original findings of early developmental dynamics of transitional subtypes of astroglia, calretinin neurons, ECM and synaptic markers presented in the SP are interesting in the light of recent concepts concerning its functional and morphogenetic role and an increasing interest in SP as a prospective substrate of abnormalities in cortical circuitry, leading to a cognitive deficit in different neurodevelopmental disorders.

Heterogeneity of free and occluded bitumen in a natural maturity sequence from Oligocene Lake Enspel

Sedimentation in Oligocene Lake Enspel was rapidly terminated by a basaltic lava flow. This introduced a preservational barrier while imparting a ‘natural flash pyrolysis’, during which the organic matter in underlying stratigraphic units was subjected to rapid thermal maturation resulting in hydrocarbon generation. Samples from these strata exhibit a steep maturity gradient (0.25–1.07% optical vitrinite reflectance, or RO) over uniform organofacies. This offers the opportunity to investigate bitumen generation during rapid thermal maturation mechanistically, in particular the nature of Bitumen 2—occluded bitumen, which is only recoverable after the digestion of the mineral matrix and was frequently dismissed as an artifact of incomplete extraction. Elaborate sequential extraction of the contact metamorphic sequence of oil shales at Enspel revealed systematic changes in bitumen composition. These trend progressively towards those of occluded bitumen, which exhibits a systematically elevated thermal maturity, a higher degree of catalytic biomarker-rearrangement and the conspicuous absence of molecular signatures from vascular plants that are present in the free bitumen. One plausible explanation involves a contribution of allochthonous clay-adsorbed organic matter to Bitumen 2. This could represent a mixture of older reworked bitumen and an early-diagenetic snapshot of clay adsorbed organic matter. Alternatively, a close association of early-generated bitumen with clay minerals may have led to enhanced isomerization and catalytically influenced ‘uniformization’ of alkane signatures. Deviations from the expected relationships between various thermal maturity parameters suggest variable dependence on the time-pressure-temperature pathway (i.e. metamorphic facies). The maturation of organic matter likely behaves differently under a contact metamorphic regime or during rapid subsidence and exhumation, as compared to slow maturation during regional subsidence. Our data also suggest that geologically brief shallow intrusive or extrusive magmatism might not be as destructive to the sedimentary hydrocarbon inventory as hitherto thought. This study draws attention to the small-scale compositional heterogeneity of bitumen that can be studied using sequential extraction methods. More importantly, it suggests that occluded bitumen could potentially harbor information on organic matter that pre-dates in situ primary productivity and may be derived from allochthonous biomass and detrital input.

Formation and development of pore structure in marine-continental transitional shale from northern China across a maturation gradient: insights from gas adsorption and mercury intrusion

The evolutionary characteristics of pore structure from Permian marine-continental transitional shale were examined based on a suite of natural shale samples from the Ningwu and Qinshui Basins in northern China, which ranged in maturity from immature (vitrinite reflectance, Ro = 0.44%) to over-mature (Ro = 1.85%). Experiments included mercury intrusion, nitrogen adsorption, and carbon dioxide adsorption, and were conducted to quantify pore volume and pore size distributions. Samples with different thermal maturity had large differences in micropore, mesopore, and macropore volume and pore size distributions. Mesopore and macropore volumes were the largest in immature shale and declined with increasing maturity to intermittent minima in the mature shale, continuing to increase to the over-mature shale. However, micropore volume gradually increased during maturation. The pore-related variances may be primarily controlled by maturity, whose effect was stronger than other factors (total organic carbon and mineral composition). During maturation, changes in pore size distribution and relative proportions of micropores, mesopores, and macropores were related to both chemical (transformation of organic matter into hydrocarbons) and mechanical (compaction) processes. Pore volume was reduced during the transition from immature to mature stage, likely mainly due to compaction instead of liquid hydrocarbon filling the pores, whereas the increase in pore volume during the transition from the mature to over-mature stage was mainly associated with the transformation of organic matter.

Induced pluripotent stem cell–based mapping of β-globin expression throughout human erythropoietic development

AbstractRobust β-globin expression in erythroid cells derived from induced pluripotent stem cells (iPSCs) increases the resolution with which red blood cell disorders such as sickle cell disease and β thalassemia can be modeled in vitro. To better quantify efforts in augmenting β-globin expression, we report the creation of a β-globin reporter iPSC line that allows for the mapping of β-globin expression throughout human erythropoietic development in real time at single-cell resolution. Coupling this tool with single-cell RNA sequencing (scRNAseq) identified features that distinguish β-globin–expressing cells and allowed for the dissection of the developmental and maturational statuses of iPSC-derived erythroid lineage cells. Coexpression of embryonic, fetal, and adult globins in individual cells indicated that these cells correspond to a yolk sac erythromyeloid progenitor program of hematopoietic development, representing the onset of definitive erythropoiesis. Within this developmental program, scRNAseq analysis identified a gradient of erythroid maturation, with β-globin–expressing cells showing increased maturation. Compared with other cells, β-globin–expressing cells showed a reduction in transcripts coding for ribosomal proteins, increased expression of members of the ubiquitin-proteasome system recently identified to be involved in remodeling of the erythroid proteome, and upregulation of genes involved in the dynamic translational control of red blood cell maturation. These findings emphasize that definitively patterned iPSC-derived erythroblasts resemble their postnatal counterparts in terms of gene expression and essential biological processes, confirming their potential for disease modeling and regenerative medicine applications.

Reciprocal interactions between epileptogenic zone and maturating cortex in children

Objectives Epilepsy in children can be devastating as it interferes with cortical maturation. Consequences could both disturb cognitive functions and create antiepileptic drugs resistance. Reciprocal interactions between epileptogenic zone and maturating cortex in children were analyzed through stereo EEG data. Methods Characteristics of neurophysiological and clinical data in focal drug-resistant epilepsy in children were analyzed both in Rothschild Foundation series and in the literature and were compared to adult data to highlight differences. We also try to find out reciprocal interactions between epileptogenic zone and maturating cortex. Results Younger children have often huge cortical lesions containing more than one epileptic zone. These regional multifocal foci could cause multiple types of seizures. The diffusion of abnormalities from the epileptogenic zone is wider than in the adult population and causes disruptions in the adjacent and also remote functional cortex. Focal pediatric epilepsy can evolve in acute worsening as prolonged status epilepticus with permanent activation of the focus, which is quite rare in adult population. Moreover, the extension of the epileptogenic zone can vary with age in the same patient and lead to appearance of new types of seizures, event after cortical resection. Surprisingly, we show that the posterior-anterior maturational gradient has no impact on the activation of epileptogenic zone. And finally, as the child is getting older, he can explain his subjective symptoms and electro-clinical correlations allow to better delineate the epileptogenic zone. Conclusion Epileptogenic zone can be multiple in children, even in surgical candidates, but electro-clinical correlations are still possible, even in younger children. Reciprocal interactions between epileptogenic zone and maturating cortex in children lead to worsen both epilepsy and cognitive development. When possible, cortical resection or disconnection should then be discussed as soon as possible in pediatric population.

New insights into island vegetation composition and species diversity-Consistent and conditional responses across contrasting insular habitats at the plot-scale.

Most island-ecology studies focus on the properties of entire island communities, thus neglecting species-environment relationships operating at the habitat-level. Habitat-specific variation in the strength and sign of these relationships will conceal patterns observed on the island scale and may preclude a mechanistic interpretation of patterns and processes. Habitat-specific species-environment relationships may also depend on the descriptor of ecological communities. This paper presents a comprehensive plot-based analysis of local vegetation composition and species diversity (species richness and species evenness) of (i) rocky shore, (ii) semi-natural grassland and (iii) coniferous forest habitats in three Baltic archipelagos in Sweden. To identify differences and consistencies between habitats and descriptors, we assessed the relative contributions of the variable-sets “region”, “topography”, “soil morphology”, “soil fertility”, “soil water”, “light availability”, “distance” and “island configuration” on local vegetation composition, species richness and species evenness. We quantified the impact of “management history” on the descriptors of local grassland communities by a newly introduced grazing history index (GHI). Unlike species diversity, changes in vegetation composition were related to most of the variable-sets. The relative contributions of the variable-sets were mostly habitat-specific and strongly contingent on the descriptor involved. Within each habitat, richness and evenness were only partly affected by the same variable-sets, and if so, their relative contribution varied between diversity proxies. Across all habitats, soil variable-sets showed highly consistent effects on vegetation composition and species diversity and contributed most to the variance explained. GHI was a powerful predictor, explaining high proportions of variation in all three descriptors of grassland species communities. The proportion of unexplained variance was habitat-specific, possibly reflecting a community maturity gradient. Our results reveal that species richness alone is an incomplete representation of local species diversity. Finally, we stress the need of including habitat-based approaches when analyzing complex species-environment relationships on islands.

Refractory spasms of focal onset—A potentially curable disease that should lead to rapid surgical evaluation

PurposeInfantile spasms (IS) can occur as the only seizure type in children with surgically amenable epilepsies. Although early surgery has shown positive effects, little is known regarding outcomes. MethodsWe retrospectively reviewed all children with IS referred to our tertiary center between 2002 and 2014 and try to define factors of outcome. ResultsSixty-eight children with focal onset seizures were referred: twenty children with a hemispheric implication and 48 with one or more lobes involved. The age of onset was significantly earlier in the hemispheric population (8.0 versus 16.7 months in the focal population). There was no difference in the age of onset between anterior and posterior onset zones, as we could expect regarding the maturation gradient. The epilepsy began earlier in life in tuberous sclerosis than in DNET. Only three children of the 48 non-hemispheric patients had a normal MRI at the time of the surgery. Temporal lobe was involved only in a third of the population. More than 86% of the patients were operated on. Patients with hemispheric lesions were operated on younger (2.6 years+/− 2.1 years) compared to 4.6+/− 3.5 years in the whole population. The most frequent etiologies were in descending order: dysplasia, ganglioglioma or dysembryoplastic tumours and tuberous sclerosis. The global seizure outcome was favorable (Engel 1a) in 74.6% of the patients, and 87.9% if the delay between the first seizure and the surgery was less than 36 months. It fell to 64.7% if the delay exceeded 50 months. ConclusionSpasms of focal onset have a similar postsurgical outcome as other seizure types so surgery may be an excellent option for treating selected patients with focal infantile spasms. Volume and type but not topography of the lesion influence the age of onset. MRI is very helpful to locate the pathology in the pediatric population, since only a small portion had a normal MRI.

Geochemical characteristics and origin of natural gas from Wufeng-Longmaxi shales of the Fuling gas field, Sichuan Basin (China)

As the first giant shale gas field in China, the Fuling gas field has recently been regarded as one of the most important regions for natural gas exploration and production in the Sichuan Basin. However, the origin of natural gas from Upper Ordovician Wufeng and the bottom of Lower Silurian Longmaxi (WL) shales in the Fuling gas field is poorly understood to limit a comprehensive understanding of gas generation, accumulation and exploration.In this work, based on molecular and stable carbon isotopic composition of a total of 24 gas samples from five shale gas wells in the Fuling field, we analyzed the geochemical characteristics and gas origin, and discussed the cause for the geochemical anomalies (carbon isotopic reversals). Molecular composition results show that gases from the Fuling gas field are dry and mainly composed of methane (97.9–98.9%), with a very low level of ethane (C2H6), propane (C3H8) and non-hydrocarbon gases (mainly CO2 and N2). These dry gases are classified as oil-associated gas and mainly derived from secondary cracking. Due to the lack of gas samples across a maturation gradient from immature to late mature, the WL gases in the Fuling field show an unclear evolution trend between the δ13C2 and wetness values; however, all these samples are located in the isotopic reversal zone. Carbon isotopes of gaseous alkanes clearly display full isotopic reversals (δ13C1>δ13C2>δ13C3), which is indicative of a relatively high thermal maturity and consistent with the measured vitrinite reflectance and modeled values (~3.0% Ro). The observed complete carbon isotopic reversals in the WL gases are caused by a combination of several mechanisms, in which isotope exchange at high temperature is the primary controlling factor. Other secondary factors include Rayleigh-type fractionation of C2H6 and C3H8, secondary cracking and gas diffusion mixing of gases at different thermal maturity levels.

Childrens’ left-turning preference is not modulated by magical ideation

ABSTRACTThe literature on human turning preferences is inconsistent. While the few studies with children below 14 years of age uniformly describe an overall left-turning (counterclockwise) tendency, a recent Internet study with more than 1500 adults found a right-sided (clockwise) bias. We set out to investigate spontaneous turning behaviour in children age 5–3 years and, based on neuropsychiatric work in adults, also explored a potential association with magical thinking. Findings indicated a clear left-turning preference, independent of a participant's sex and handedness. Whether a child responded a question about the existence of extrasensory communication in the affirmative or not was unrelated to direction and size of turning bias and lateral preference. Our results are consistent with a left-sided turning preference reported for children, but in opposition to the clockwise bias recently described in a large-scale study with adults. Whether they point to a maturational gradient in the preferred direction of spontaneous whole-body rotation or rather to a lack of comparability between measures used in observational versus Internet-based studies remains to be further investigated. Regarding a purported association between body turns and magical thinking, our study is preliminary, as only one single question was used to probe the latter.

Leadership and Power in Public Organizations: Cross-Country Analysis from the Brazilian Perspective

The aim of this paper is to present the actual scenario of leadership and power in the public sector as well as the challenges in the further development of theory in this subject. This paper shows a cross country analysis conducted by analyzing the themes approached by recent literature in different countries related to this subject-leadership and power in public organizations. The documental analysis allows-besides the comparison-an integrative review about leadership and power in public organizations, what also presents the evolution of the theme in the last few years. The integrative review is conducted by summarizing available publications. It was identified authors, contexts, perspectives and focus, then synthesized main results, findings and conclusions. Then the cross-country analysis shows that different countries have different trending topics and some patterns were detected. As observed in the leadership literature values such as honesty and its impacts in leader behavior-and leadership process-are the most sensitive challenges in public service on lower adjusted GDP countries. The lack of ethics may result in significant misuse of power. There is an urgency in to design metrics about this kind of power misuse to avoid individuals to destroy organizations while achieving personal goals. It is presented a maturity gradient, from basic ethics to professionalization and competences on process-till efficacy. So this study presents trending topics embraced by leadership and power in public organizations’ nowadays, a debate and integrative review on these topics.

The source kitchen of the Niger Delta oils: case study on Nembe Creek E1.0 and the Kolo Creek E2.0 reservoirs

The source kitchen of a petroleum system is that part of the pod of active source rock which is mature and generates the petroleum that charges the reservoir rock. The location of the source kitchen of a petroleum system is vital to the explorationist, its knowledge fosters the prediction of migratory pathways and the migratory losses prior to present times, also estimates potential volume of accumulation. Hither to, mapping of the petroleum basins was based on total organic carbon (TOC), hydrogen index (HI) signatures and maturity history of the source rock and has been used as the basis to suggest locations of petroleum kitchens. In contemporary times, 4D seismic or 3D time lapse geochemistry had been used to suggest location of source kitchen. However, settled is the concept of lateral maturity gradients, implying that within reservoir scales of a kilometer to tens of kilometers, regional petroleum emplacement direction could be deduced from subtle changes in maturity of successive charges of petroleum into the reservoir. In this study, the sterane isomerization ratio (20S/20S + 20R αααC29) was used to determine the maturities of the hydrocarbons from various wells in the Kolo Creek and the Nembe Creek reservoirs. Subtle increases in maturities were observed to be in a NE–SW direction for the Kolo Creek reservoir and in a NW–SE direction for the Nembe Creek reservoir. The direction of increasing maturities relative to the location of the reservoirs could be extrapolated for both reservoirs towards offshore Gulf of Guinea; this is invariably the direction of location of the source kitchen for the Niger Delta oils.

Basin deconstruction–construction: Seeking thermal–tectonic consistency through the integration of geochemical thermal indicators and seismic fault mechanical stratigraphy ​– Example from Faras Field, North Western Desert, Egypt

To construct a model of a sedimentary basin's thermal tectonic history is first to deconstruct it: taking apart its geological elements, searching for its initial conditions, and then to reassemble the elements in the temporal order that the basin is assumed to have evolved. Two inherent difficulties implicit to the analysis are that most organic thermal indicators are cumulative, irreversible and a function of both temperature and time and the non-uniqueness of crustal strain histories which complicates tectonic interpretations. If the initial conditions (e.g. starting maturity of the reactants and initial crustal temperature) can be specified and the boundary conditions incrementally designated from changes in the lithospheric heat engine owing to stratigraphic structural constraints, then the number of pathways for the temporal evolution of a basin is greatly reduced. For this investigation, model input uncertainties are reduced through seeking a solution that iteratively integrates the geologically constrained tectonic subsidence, geochemically constrained thermal indicators, and geophysically constrained fault mechanical stratigraphy.The Faras oilfield in the Abu Gharadig Basin, North Western Desert, Egypt, provides an investigative example of such a basin's deconstructive procedure. Multiple episodes of crustal extension and shortening are apparent in the tectonic subsidence analyses which are constrained from the fault mechanical stratigraphy interpreted from reflection seismic profiles. The model was iterated with different thermal boundary conditions until outputs best fit the geochemical observations. In so doing, the thermal iterations demonstrate that general relationship that basin heat flow increases decrease vertical model maturity gradients, increases in surface temperatures shift vertical maturity gradients linearly to higher values, increases in sediment conductivities lower vertical maturities with depth, and the addition of “ghost” layers (those layers removed) prior to the erosional event increase maturities beneath, and conversely. These integrated constraints upon the basin evolution model indicate that the principal source rocks, Khatatba and the lowest part of the Alam El Bueib formations, entered the oil window at approximately 95 Ma and the gas window at approximately 25 Ma. The upper part of the Alam El Bueib Formation is within the oil window at the present day.Establishing initial and boundary value conditions for a basin's thermal evolution when geovalidated by the integration of seismic fault mechanical stratigraphy, tectonic subsidence analysis, and organic geochemical maturity indicators provides a powerful tool for optimizing petroleum exploration in both mature and frontier basins.