165 research outputs found

    Morphological analysis of stylolites for paleostress estimation in limestones surrounding the Andra Underground Research Laboratory site

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    We develop and test a methodology to infer paleostress from the morphology of stylolites within borehole cores. This non-destructive method is based on the analysis of the stylolite trace along the outer cylindrical surface of the cores. It relies on an automatic digitization of high-resolution photographs and on the spatial Fourier spectrum analysis of the stylolite traces. We test and show, on both synthetic and natural examples, that the information from this outer cylindrical surface is equivalent to the one obtained from the destructive planar sections traditionally used. The assessment of paleostress from the stylolite morphology analysis is made using a recent theoretical model, which links the morphological properties to the physical processes acting during stylolite evolution. This model shows that two scaling regimes are to be expected for the stylolite height power spectrum, separated by a cross-over length that depends on the magnitude of the paleostress during formation. We develop a non linear fit method to automatically extract the cross-over lengths from the digitized stylolite profiles. Results on cores from boreholes drilled in the surroundings of the Andra Underground Research Laboratory located at Bure, France, show that different groups of sedimentary stylolites can be distinguished, and correspond to different estimated vertical paleostress values. For the Oxfordian formation, one group of stylolites indicate a paleostress of around 10 MPa, while another group yields 15 MPa. For the Dogger formation, two stylolites indicate a paleostress of around 10 MPa, while others appear to have stopped growing at paleostresses between 30 and 22 MPa, starting at an erosion phase that initiated in the late Cretaceous and continues today. This method has a high potential for further applications on reservoirs or other geological contexts where stylolites are present.Comment: International Journal of Rock Mechanics and Mining Sciences (2013) online firs

    Forholdet mellom samhandlingsprosessen og resultatet i en prosjektfase. En kvalitativ studie av delprosjektet «Regnskapsmodulen i Visma» i sammenslåingen av Troms og Finnmark Fylkeskommune

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    Temaet for denne masteroppgaven er samhandlingsprosessen i prosjektfasen. Oppgaven undersøker samhandling gjennom måten ulike aktører interagerer og samarbeider med hverandre i en prosjektorganisering. Det stilles spørsmål til hvordan man kan forstå delprosjektet «Regnskapsmodulen i Visma» i sammenslåingsprosessen av Troms og Finnmark fylkeskommune, som et resultat av samhandlingen. Hensikten med oppgaven er å medvirke til økt kunnskap rundt viktigheten av samhandling i form av måten det arbeides på i en prosjektfase. Problemstillingen for vår studie er: «Hvordan kan regnskapsmodulen i det nye økonomisystemet forstås som et resultat av samhandlingsprosessen i prosjektfasen?» Problemstillingen besvares gjennom en kvalitativ intervjustudie, der samhandlingen mellom prosjektmedlemmene fra de tidligere organisasjonene Troms Fylkeskommune og Finnmark Fylkeskommune studeres. Studiens formål er å beskrive hvordan samhandlingsprosessen har utspilt seg og hvilken effekt denne har hatt på det resultatet som oppnås i prosjektet. Dette tilsier at vi studerer arbeidet som skjer rundt regnskapsmodulen i deres nye økonomisystem.. Det ble intervjuet 9 aktører som var knyttet til delprosjektet og som arbeidet med regnskapsmodulen, hvor alle var ansatt i tidligere Troms Fylkeskommune. For å belyse problemstillingen benyttes det teoretiske begrepet prosjektorganisering, og som er det vi refererer til som prosjektfasen. Innen prosjektorganisering tar vi for oss samhandling, hvor vi studerer ulike dimensjoner ved samhandlingsprosessen. Vi har valgt å se nærmere på samhandlingsdimensjonene tid, mål, involvering, beslutning og kommunikasjon. Av disse dimensjonene utformet vi tre egenkomponerte perspektiver; Koalisjon, Ad-Hoc og Perfekt. Hvert perspektiv beskriver ulike samhandlingsprosesser, ettersom ulike premisser ved dimensjonene vektlegges. Med dette utleder hvert perspektiv ulike forventninger knyttet til prosjektets resultat. Sentrale empiriske funn viser at tidsrammen i sammenslåingsprosessen var kort. Dette førte til at koordinering av mål var krevende, innspill fra brukerne av det nye økonomisystemet ble ikke prioritert, beslutningstakingen ble hyppigere for å unngå stagnering i arbeidet, samt at kommunikasjonen var mindre effektiv mellom aktørene. Det konkluderes at deres samhandlingsprosess best forklares av Perspektiv Ad-Hoc, hvilket utleder forventninger til at regnskapsmodulen vil være uferdig, men forsvarlig til drift fra 1. januar 2020. I tillegg dekkes enkelte empiriske funn av Perspektiv Koalisjon, hvilket gjør at det kan forventes en forlengelse av prosjektfasen etter at prosjektet opphører eller eventuelt en reversering. Nøkkelord: Prosjektorganisering, prosjektfase, samhandling, regionreformen, økonomisyste

    Modeling the growth of stylolites in sedimentary rocks

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    [1] Stylolites are ubiquitous pressure solution seams found in sedimentary rocks. Their morphology is shown to follow two self-affine regimes. Analyzing the scaling properties of their height over their average direction shows that (1) at small scale, they are self-affine surfaces with a Hurst exponent around 1, and (2) at large scale, they follow another self-affine scaling with Hurst exponent around 0.5. In the present paper, we show theoretically the influence of the main principal stress and the local geometry of the stylolitic interface on the dissolution reaction rate. We compute how it is affected by the deviation between the principal stress axis and the local interface between the rock and the soft material in the stylolite. The free energy entering in the dissolution reaction kinetics is expressed from the surface energy term and via integration from the stress perturbations due to these local misalignments. The resulting model shows the interface evolution at different stress conditions. In the stylolitic case, i.e., when the main principal stress is normal to the interface, two different stabilizing terms dominate at small and large scales which are linked respectively to the surface energy and to the elastic interactions. Integrating the presence of small-scale heterogeneities related to the rock properties of the grains in the model leads to the formulation of a Langevin equation predicting the dynamic evolution of the surface. This equation leads to saturated surfaces obeying the two observed scaling laws. Analytical and numerical analysis of this surface evolution model shows that the crossover length separating both scaling regimes depends directly on the applied far-field stress magnitude. This method gives the basis for the development of a paleostress magnitude marker. We apply the computation of this marker, i.e., the morphological analysis, on a stylolite found in the Dogger limestone layer located in the neighborhood of the ANDRA Underground Research Laboratory at Bure (eastern France). The results are consistent with the two scaling regimes expected, and the practical determination of the major principal paleostress, from the estimation of a crossover length, is illustrated on this example

    Human cytomegalovirus infection is associated with increased expression of the lissencephaly gene PAFAH1B1 encoding LIS1 in neural stem cells and congenitally infected brains

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    peer reviewedCongenital infection of the central nervous system by human cytomegalovirus (HCMV) is a leading cause of permanent sequelae, including mental retardation or neurodevelopmental abnormalities. The most severe complications include smooth brain or polymicrogyria, which are both indicative of abnormal migration of neural cells, although the underlying mechanisms remain to be determined. To gain better insight on the pathogenesis of such sequelae, we assessed the expression levels of a set of neurogenesis-related genes, using HCMV-infected human neural stem cells derived from embryonic stem cells (NSCs). Among the 84 genes tested, we found dramatically increased expression of the gene PAFAH1B1, encoding LIS1 (lissencephaly-1), in HCMV-infected versus uninfected NSCs. Consistent with these ndings, western blotting and immunouorescence analyses conrmed the increased levels of LIS1 in HCMV-infected NSCs at the protein level. We next assessed the migratory abilities of HCMV-infected NSCs and observed that infection strongly impaired the migration of NSCs, without detectable effect on their proliferation. Moreover, we observed increased immunostaining for LIS1 in brains of congenitally infected fetuses, but not in control samples, highlighting the clinical relevance of our ndings. Of note, PAFAH1B1 mutations (resulting in either haploinsufciency or gain of function) are primary causes of hereditary neurodevelopmental diseases. Notably, mutations resulting in PAFAH1B1 haploinsufciency cause classic lissencephaly. Taken together, our ndings suggest that PAFAH1B1 is a critical target of HCMV infection. They also shine a new light on the pathophysiological basis of the neurological outcomes of congenital HCMV infection, by suggesting that defective neural cell migration might contribute to the pathogenesis of the neurodevelopmental sequelae of infectio

    British Gynaecological Cancer Society recommendations and guidance on patient-initiated follow-up (PIFU)

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    The National Cancer Survivorship Initiative through the National Health Service (NHS) improvement in the UK started the implementation of stratified pathways of patient-initiated follow-up (PIFU) across various tumor types. Now the initiative is continued through the Living With and Beyond Cancer program by NHS England. Evidence from non-randomized studies and systematic reviews does not demonstrate a survival advantage to the long-established practice of hospital-based follow-up regimens, traditionally over 5 years. Evidence shows that patient needs are inadequately met under the traditional follow-up programs and there is therefore an urgent need to adapt pathways to the needs of patients. The assumption that hospital-based follow-up is able to detect cancer recurrences early and hence improve patient prognosis has not been validated. A recent survey demonstrates that follow-up practice across the UK varies widely, with telephone follow-up clinics, nurse-led clinics and PIFU becoming increasingly common. There are currently no completed randomized controlled trials in PIFU in gynecological malignancies, although there is a drive towards implementing PIFU. PIFU aims to individualize patient care, based on risk of recurrence and holistic needs, and optimizing resources. The British Gynaecological Cancer Society wishes to provide the gynecological oncology community with guidance and a recommendations statement regarding the value, indications, and limitations of PIFU in endometrial, cervical, ovarian, and vulvar cancers in an effort to standardize practice and improve patient care. [Abstract copyright: © IGCS and ESGO 2020. No commercial re-use. See rights and permissions. Published by BMJ.

    British Gynaecological Cancer Society Recommendations for Evidence Based, Population Data Derived Quality Performance Indicators for Ovarian Cancer

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    Ovarian cancer survival in the UK lags behind comparable countries. Results from the ongoing National Ovarian Cancer Audit feasibility pilot (OCAFP) show that approximately 1 in 4 women with advanced ovarian cancer (Stage 2, 3, 4 and unstaged cancer) do not receive any anticancer treatment and only 51% in England receive international standard of care treatment, i.e., the combination of surgery and chemotherapy. The audit has also demonstrated wide variation in the percentage of women receiving anticancer treatment for advanced ovarian cancer, be it surgery or chemotherapy across the 19 geographical regions for organisation of cancer delivery (Cancer Alliances). Receipt of treatment also correlates with survival: 5 year Cancer survival varies from 28.6% to 49.6% across England. Here, we take a systems wide approach encompassing both diagnostic pathways and cancer treatment, derived from the whole cohort of women with ovarian cancer to set out recommendations and quality performance indicators (QPI). A multidisciplinary panel established by the British Gynaecological Cancer Society carefully identified QPI against criteria: metrics selected were those easily evaluable nationally using routinely available data and where there was a clear evidence base to support interventions. These QPI will be valuable to other taxpayer funded systems with national data collection mechanisms and are to our knowledge the only population level data derived standards in ovarian cancer. We also identify interventions for Best practice and Research recommendations

    Paving the way towards future-proofing our crops

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    To meet the increasing global demand for food, feed, fibre and other plant-derived products, a steep increase in crop productivity is a scientifically and technically challenging imperative. The CropBooster-P project, a response to the H2020 call ‘Future proofing our plants’, is developing a roadmap for plant research to improve crops critical for the future of European agriculture by increasing crop yield, nutritional quality, value for non-food applications and sustainability. However, if we want to efficiently improve crop production in Europe and prioritize methods for crop trait improvement in the coming years, we need to take into account future socio-economic, technological and global developments, including numerous policy and socio-economic challenges and constraints. Based on a wide range of possible global trends and key uncertainties, we developed four extreme future learning scenarios that depict complementary future developments. Here, we elaborate on how the scenarios could inform and direct future plant research, and we aim to highlight the crop improvement approaches that could be the most promising or appropriate within each of these four future world scenarios. Moreover, we discuss some key plant technology options that would need to be developed further to meet the needs of multiple future learning scenarios, such as improving methods for breeding and genetic engineering. In addition, other diverse platforms of food production may offer unrealized potential, such as underutilized terrestrial and aquatic species as alternative sources of nutrition and biomass production. We demonstrate that although several methods or traits could facilitate a more efficient crop production system in some of the scenarios, others may offer great potential in all four of the future learning scenarios. Altogether, this indicates that depending on which future we are heading toward, distinct plant research fields should be given priority if we are to meet our food, feed and non-food biomass production needs in the coming decades

    Management of anaphylaxis due to COVID-19 vaccines in the elderly

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    Older adults, especially men and/or those with diabetes, hypertension, and/or obesity, are prone to severe COVID-19. In some countries, older adults, particularly those residing in nursing homes, have been prioritized to receive COVID-19 vaccines due to high risk of death. In very rare instances, the COVID-19 vaccines can induce anaphylaxis, and the management of anaphylaxis in older people should be considered carefully. An ARIA-EAACI-EuGMS (Allergic Rhinitis and its Impact on Asthma, European Academy of Allergy and Clinical Immunology, and European Geriatric Medicine Society) Working Group has proposed some recommendations for older adults receiving the COVID-19 vaccines. Anaphylaxis to COVID-19 vaccines is extremely rare (from 1 per 100,000 to 5 per million injections). Symptoms are similar in younger and older adults but they tend to be more severe in the older patients. Adrenaline is the mainstay treatment and should be readily available. A flowchart is proposed to manage anaphylaxis in the older patients.Peer reviewe

    Multiple Measures of Adiposity Are Associated with Mean Leukocyte Telomere Length in the Northern Finland Birth Cohort 1966

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    Studies of leukocyte telomere length (LTL) and adiposity have produced conflicting results, and the relationship between body mass index (BMI) and telomere length throughout life remains unclear. We therefore tested association of adult LTL measured in 5,598 participants with: i) childhood growth measures (BMI and age at adiposity rebound (AR)); ii) change in BMI from childhood to adulthood and iii) adult BMI, waist-to-hip ratio (WHR), body adiposity index (BAI). Childhood BMI at AR was positively associated with LTL at 31 years in women (P = 0.041). Adult BMI and WHR in both men (P = 0.025 and P = 0.049, respectively) and women (P = 0.029 and P = 0.008, respectively), and BAI in women (P = 0.021) were inversely associated with LTL at 31 years. An increase in standardised BMI between early childhood and adulthood was associated with shorter adult LTL in women (P = 0.008). We show that LTL is inversely associated with multiple measures of adiposity in both men and women. Additionally, BMI increase in women from childhood to adulthood is associated with shorter telomeres at age 31, potentially indicating accelerated biological ageing

    Cabbage and fermented vegetables : From death rate heterogeneity in countries to candidates for mitigation strategies of severe COVID-19

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    Large differences in COVID-19 death rates exist between countries and between regions of the same country. Some very low death rate countries such as Eastern Asia, Central Europe, or the Balkans have a common feature of eating large quantities of fermented foods. Although biases exist when examining ecological studies, fermented vegetables or cabbage have been associated with low death rates in European countries. SARS-CoV-2 binds to its receptor, the angiotensin-converting enzyme 2 (ACE2). As a result of SARS-CoV-2 binding, ACE2 downregulation enhances the angiotensin II receptor type 1 (AT(1)R) axis associated with oxidative stress. This leads to insulin resistance as well as lung and endothelial damage, two severe outcomes of COVID-19. The nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the most potent antioxidant in humans and can block in particular the AT(1)R axis. Cabbage contains precursors of sulforaphane, the most active natural activator of Nrf2. Fermented vegetables contain many lactobacilli, which are also potent Nrf2 activators. Three examples are: kimchi in Korea, westernized foods, and the slum paradox. It is proposed that fermented cabbage is a proof-of-concept of dietary manipulations that may enhance Nrf2-associated antioxidant effects, helpful in mitigating COVID-19 severity.Peer reviewe
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