177 research outputs found

    Direct gas-in-place measurements prove much higher production potential than expected for shale formations

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    Shale gas exploitation has been the game-changer in energy development of the past decade. However, the existing methods of estimating gas in place in deep formations suffer from large uncertainties. Here, we demonstrate, by using novel high-pressure experimental techniques, that the gas in place within deep shale gas reservoirs can be up to five times higher than that estimated by implementing industry standard approaches. We show that the error between our laboratory approach and the standard desorption test is higher for gases with heavier compositions, which are of strongest commercial interests. The proposed instrumentation is reliable for deep formations and, provides quick assessment of the potential for the gas in place, which could be useful for assessing hydrocarbon reservoirs, and the potential for geological carbon sequestration of a given formation

    Cingulum microstructure predicts cognitive control in older age and mild cognitive impairment

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    Cognitive control, an important facet of human cognition, provides flexibility in response to varying behavioral demands. Previous work has focused on the role of prefrontal cortex, notably the anterior cingulate cortex. However, it is now clear that this is one node of a distributed cognitive network. In this emerging network view, structural connections are inherent elements, but their role has not been emphasized. Furthermore, lesion and functional imaging studies have contributed little knowledge about anatomical segregation, functional specialization, and behavioral importance of white matter connections. The relationship between cognitive control and microstructure of connections within the cingulum, a major white matter tract and conduit of projections to prefrontal sites, was probed in vivo inhumans with diffusion MRI. Twenty healthy controls and 25 individuals with amnestic mild cognitive impairment (MCI), an early stage of age-associated cognitive deterioration, underwent cognitive testing, including several measures of cognitive control. For each individual, the anterior, middle, posterior, and parahippocampal portions of the cingulum bundle were reconstructed separately using deterministic tractography and anatomical landmarks. Micro structural variation in the left anterior cingulum was closely related to inter individual control based on verbal or symbolic rules. Errors in a task that involved maintenance of spatial rules were largely restricted to patients with MCI and were related, additionally, to right anterior cingulum microstructure. Cognitive control in MCI was also independently related to posterior parahippocampal connections. These results show how specific subpopulations of connections are critical in cognitive control and illustrate fine-grained anatomical specializations in the white matter infrastructure of this network

    Haploinsufficiency of the schizophrenia and autism risk gene Cyfip1 causes abnormal postnatal hippocampal neurogenesis through microglial and Arp2/3 mediated actin dependent mechanisms

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    Genetic risk factors can significantly increase chances of developing psychiatric disorders, but the underlying biological processes through which this risk is effected remain largely unknown. Here we show that haploinsufficiency of Cyfip1, a candidate risk gene present in the pathogenic 15q11.2(BP1–BP2) deletion may impact on psychopathology via abnormalities in cell survival and migration of newborn neurons during postnatal hippocampal neurogenesis. We demonstrate that haploinsufficiency of Cyfip1 leads to increased numbers of adult-born hippocampal neurons due to reduced apoptosis, without altering proliferation. We show this is due to a cell autonomous failure of microglia to induce apoptosis through the secretion of the appropriate factors, a previously undescribed mechanism. Furthermore, we show an abnormal migration of adult-born neurons due to altered Arp2/3 mediated actin dynamics. Together, our findings throw new light on how the genetic risk candidate Cyfip1 may influence the hippocampus, a brain region with strong evidence for involvement in psychopathology

    The influence of candidates’ physical attributes on assessors’ ratings in clinical practice

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    Background Assessments of physician competence in the work-place are common and often contribute to high-stakes assessments. Previous research suggests that assessors’ judgements can be influenced by candidates’ physical attributes. We investigated whether simulated candidates’ scores were influenced by assessor bias based on tattoos, hair colour, and a regional accent. Methods We used an experimental, video-based, single-blinded, randomised, internet-based design. We created videos of simulated medical intern performances of a clinical examination at four different standards of competence. Four videos were also created of simulated candidates performing at a ‘clear pass’ standard, with either no stereotypical attribute (CPX), purple hair (CPH), tattoos (CPT) or a Liverpool English accent (CPA). Assessors were randomly assigned to watch five videos including the “clear pass” candidate without an attribute and one of the “clear pass” candidates with an attribute and asked to give an overall global grade for each candidate. We compared the global grades for the clear pass candidates with and without attributes. Results Ninety-eight assessors were included in the analysis. The total scores for the candidates with stereotyped attributes were not significantly lower than the candidate with no attribute. Assessors showed moderate levels of agreement between the global grades awarded for all the candidates. The global grades awarded to candidate with a stereotypical attribute were not significantly lower than for those without. Conclusions The presence of tattoos, purple hair, or a regional accent did not systematically negatively influence the grade or score awarded by assessors to candidates in observed clinical examination scenarios

    Dissociable effects of complement C3 and C3aR on survival and morphology of adult born hippocampal neurons, pattern separation, and cognitive flexibility in male mice

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    Adult hippocampal neurogenesis (AHN) is a form of ongoing plasticity in the brain that supports specific aspects of cognition. Disruptions in AHN have been observed in neuropsychiatric conditions presenting with inflammatory components and are associated with impairments in cognition and mood. Recent evidence highlights important roles of the complement system in synaptic plasticity and neurogenesis during neurodevelopment and in acute learning and memory processes. In this work we investigated the impact of the complement C3/C3aR pathway on AHN and its functional implications for AHN-related behaviours. In C3−/− mice, we found increased numbers and accelerated migration of adult born granule cells, indicating that absence of C3 leads to abnormal survival and distribution of adult born neurons. Loss of either C3 or C3aR affected the morphology of immature neurons, reducing morphological complexity, though these effects were more pronounced in the absence of C3aR. We assessed functional impacts of the cellular phenotypes in an operant spatial discrimination task that assayed AHN sensitive behaviours. Again, we observed differences in the effects of manipulating C3 or C3aR, in that whilst C3aR−/− mice showed evidence of enhanced pattern separation abilities, C3−/− mice instead demonstrated impaired behavioural flexibility. Our findings show that C3 and C3aR manipulation have distinct effects on AHN that impact at different stages in the development and maturation of newly born neurons, and that the dissociable cellular phenotypes are associated with specific alterations in AHN-related behaviours

    Gossip as a Burdened Virtue

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    Gossip is often serious business, not idle chitchat. Gossip allows those oppressed to privately name their oppressors as a warning to others. Of course, gossip can be in error. The speaker may be lying or merely have lacked sufficient evidence. Bias can also make those who hear the gossip more or less likely to believe the gossip. By examining the social functions of gossip and considering the differences in power dynamics in which gossip can occur, we contend that gossip may be not only permissible but virtuous, both as the only reasonable recourse available and as a means of resistance against oppression

    Hygiene inspections on passenger ships in Europe - an overview

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    <p>Abstract</p> <p>Background</p> <p>Hygiene inspections on passenger ships are important for the prevention of communicable diseases. The European Union (EU) countries conduct hygiene inspections on passenger ships in order to ensure that appropriate measures have been taken to eliminate potential sources of contamination which could lead to the spread of communicable diseases. This study was implemented within the framework of the EU SHIPSAN project and it investigates the legislation applied and practices of hygiene inspections of passenger ships in the EU Member States (MS) and European Free Trade Association countries.</p> <p>Methods</p> <p>Two questionnaires were composed and disseminated to 28 countries. A total of 92 questionnaires were completed by competent authorities responsible for hygiene inspections (n = 48) and the creation of legislation (n = 44); response rates were 96%, and 75.9%, respectively.</p> <p>Results</p> <p>Out of the 48 responding authorities responsible for hygiene inspections, a routine programme was used by 19 (39.6%) of these to conduct inspections of ships on national voyages and by 26 (54.2%) for ships on international voyages. Standardised inspection forms are used by 59.1% of the authorities. A scoring inspection system is applied by five (11.6%) of the 43 responding authorities. Environmental sampling is conducted by 84.1% of the authorities (37 out of 44). The inspection results are collected and analysed by 54.5% (24 out of 44) of the authorities, while 9 authorities (20.5%) declared that they publish the results. Inspections are conducted during outbreak investigations by 75% and 70.8% of the authorities, on ships on national and international voyages, respectively. A total of 31 (64.6%) and 39 (81.3%) authorities conducted inspections during complaint investigations on ships on international and on national voyages, respectively. Port-to-port communication between the national port authorities was reported by 35.4% (17 out of 48) of the responding authorities and 20.8% (10 out of 48) of the port authorities of other countries.</p> <p>Conclusion</p> <p>This study revealed a diversity of approaches and practices in the conduct of inspections, differences in the qualifications/knowledge/experience of inspectors, the legislation applied during inspections, and the lack of communication and training among many EU countries. An integrated European inspection programme involving competent expert inspectors in each EU Member States and special training for ship hygiene delivered to crew members and inspectors would help to minimize the risk of communicable diseases. Common inspection tools at a European level for hygiene inspection practices and port-to-port communication are needed.</p

    Mathematical modelling of cytokines, MMPs and fibronectin fragments in osteoarthritic cartilage

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    Osteoarthritis (OA) is a degenerative disease which causes pain and stiffness in joints. OA progresses through excessive degradation of joint cartilage, eventually leading to significant joint degeneration and loss of function. Cytokines, a group of cell signalling proteins, present in raised concentrations in OA joints, can be classified into pro-inflammatory and anti-inflammatory groups. They mediate cartilage degradation through several mechanisms, primarily the up-regulation of matrix metalloproteinases (MMPs), a group of collagen-degrading enzymes. In this paper we show that the interactions of cytokines within cartilage have a crucial role to play in OA progression and treatment. We develop a four-variable ordinary differential equation model for the interactions between pro- and anti-inflammatory cytokines, MMPs and fibronectin fragments (Fn-fs), a by-product of cartilage degradation and upregulator of cytokines. We show that the model has four classes of dynamic behaviour: homoeostasis, bistable inflammation, tristable inflammation and persistent inflammation. We show that positive and negative feedbacks controlling cytokine production rates can determine either a pre-disposition to OA or initiation of OA. Further, we show that manipulation of cytokine, MMP and Fn-fs levels can be used to treat OA, but we suggest that multiple treatment targets may be essential to halt or slow disease progression

    Complement C3 and C3aR mediate different aspects of emotional behaviours; relevance to risk for psychiatric disorder

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    Complement is a key component of the immune system with roles in inflammation and host-defence. Here we reveal novel functions of complement pathways impacting on emotional reactivity of potential relevance to the emerging links between complement and risk for psychiatric disorder. We used mouse models to assess the effects of manipulating components of the complement system on emotionality. Mice lacking the complement C3a Receptor (C3aR−/−) demonstrated a selective increase in unconditioned (innate) anxiety whilst mice deficient in the central complement component C3 (C3−/−) showed a selective increase in conditioned (learned) fear. The dissociable behavioural phenotypes were linked to different signalling mechanisms. Effects on innate anxiety were independent of C3a, the canonical ligand for C3aR, consistent with the existence of an alternative ligand mediating innate anxiety, whereas effects on learned fear were due to loss of iC3b/CR3 signalling. Our findings show that specific elements of the complement system and associated signalling pathways contribute differentially to heightened states of anxiety and fear commonly seen in psychopathology
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