Static and dynamic effective stress coefficient of chalk

Deformation of a hydrocarbon reservoir can ideally be used to estimate the effective stress acting on it. The effective stress in the subsurface is the difference between the stress due to the weight of the sediment and a fraction (effective stress coefficient) of the pore pressure. The effective stress coefficient is thus relevant for studying reservoir deformation and for evaluating 4D seismic for the correct pore pressure prediction. The static effective stress coefficient [Formula: see text] is estimated from mechanical tests and is highly relevant for effective stress prediction because it is directly related to mechanical strain in the elastic stress regime. The corresponding dynamic effective stress coefficient [Formula: see text] is easy to estimate from density and velocity of acoustic (elastic) waves. We studied [Formula: see text] and [Formula: see text] of chalk from the reservoir zone of the Valhall field, North Sea, and found that [Formula: see text] and [Formula: see text] vary with differential stress (overburden stress-pore pressure). For Valhall reservoir chalk with 40% porosity, [Formula: see text] ranges between 0.98 and 0.85 and decreases by 10% if the differential stress is increased by 25 MPa. In contrast, for chalk with 15% porosity from the same reservoir, [Formula: see text] ranges between 0.85 and 0.70 and decreases by 5% due to a similar increase in differential stress. Our data indicate that [Formula: see text] measured from sonic velocity data falls in the same range as for [Formula: see text], and that [Formula: see text] is always below unity. Stress-dependent behavior of [Formula: see text] is similar (decrease with increasing differential stress) to that of [Formula: see text] during elastic deformation caused by pore pressure buildup, for example, during waterflooding. By contrast, during the increase in differential stress, as in the case of pore pressure depletion due to production, [Formula: see text] increases with stress while [Formula: see text] decreases.</jats:p

Intergenerational spillover effects of language training for refugees

Children of refugees are among the most economically disadvantaged youth in several European countries. They are more likely to drop out of school and to commit crime. We find that a reform in Denmark in 1999 that expanded language training for adult refugees and was shown to improve their earnings and job market outcomes permanently, also increased lower secondary school completion rates and decreased juvenile crime rates for their children. The crime effect is entirely due to boys who were below school age when their parents received language training. The older cohorts who were in elementary school when their parents received language training performed better in lower secondary school. Boys were more likely to finish lower secondary school and to sit the final exams, and girls achieved higher grade point averages in the exams

Co-Parenting for Successful Kids: Impacts and Implications

We examined the impacts of the Co-Parenting for Successful Kids program offered by University of Nebraska Extension. Using a sample of 2,622 parents who participated in the program in 2015, we measured their knowledge change and ability to perform cooperative coparenting behaviors. Results suggest that the program effectively improved participants\u27 coparenting knowledge and ability to use behaviors such as understanding and supporting children in developmentally appropriate ways, enhancing communication skills, and developing parenting plans. In examining group differences, we found that parents of infants and toddlers benefited the most from the program. Suggestions on program development and evaluation are discussed

Measurement and simulation of reflector antenna

Well-established procedures are consolidated to determine the associated measurement uncertainty for a given antenna and measurements scenario [1-2]. Similar criteria for establishing uncertainties in numerical modelling of the same antenna are still to be established. In this paper, we investigate the achievable agreement between antenna measurement and simulation when external error sources are minimized. The test object, is a reflector fed by a wideband dual ridge horn (SR40-A and SH4000). The highly stable reference antenna has been selected to minimize uncertainty related to finite manufacturing and material parameter accuracy. Two frequencies, 10.7GHz and 18GHz have been selected for detailed investigation

Familiers kosmopolitiske uddannelsesstrategier – Et spørgsmål om migration og investering i distinktiv kapital

Artiklen viser, at der er en nær sammenhæng mellem social baggrund og gennemførelse af eliteuddannelse og ikke-eliteuddannelse blandt en gruppe af danske migranter med minimum fem års ophold i udlandet. Vi tilføjer en ny rekonversionsstrategi til Pierre Bourdieus batteri af strategier udfoldet i La Noblesse d’État, en udvandrings-strategi med henblik på erhvervelse af uddannelseskapital. Især personer med veluddannede forældre har en forøget sandsynlighed for at erobre en universitetsuddannelse på en eliteinstitution, navnlig i ”zones of prestige”, det vil sige i England og USA, som relativt set har de største udbud af distinktive universitetsinstitutioner. En gruppe af migranter gennemfører en udenlandsk universitetsuddannelse på ikke-elite institutioner, hvilket kan afspejle en form for kompensatorisk strategi, som udmøntes i social uddannelsesmobilitet. Forældrene til børn, der opnår en universitetsgrad fra udlandet, har desuden selv en betydelig kosmopolitisk erfaring. Endeligt finder vi markante kønsforskelle. Søgeord: Transnationale uddannelsesstrategier, kosmopolitisk kapital, kulturel kapital, migration, rekonversionsstrategier, Bourdieu. ENGELSK ABSTRACT: Martin D. Munk, Mette Foged, and Andreas M. Mulvad: The Cosmopolitan Educational Strategies of Families. A Question of Migration and Investment in Distinctive Capital This paper shows that there is a strong correlation between social origin and attaining non-élite and especially élite education abroad for a group of long-term emigrants from Denmark. We suggest acquisition of distinctive educational capital abroad as a new investment and reconversion strategy that supplements the portfolio of (national) strategies developed by Bourdieu in La Noblesse d’État. In particular, people with highly educated parents have a greater tendency to obtain university education from an élite institution abroad, especially in ”zones of prestige”. Because England and the US have the greatest number of distinctive institutions of higher education, these countries are attracting the majority of Danes who emigrate for at least five years and obtain university education abroad. We suggest that the weaker selection into non-élite institutions reflects a sort of compensational strategy which leads to upward social educational mobility. Parents of children who migrate and undertake university education abroad have often studied or worked abroad themselves, so the intergenerational transmission of cosmopolitan capital follows the same pattern as the intergenerational transmission of the educational level. Furthermore, we find strong gender differences for instance with respect to motivations for studying abroad and the relative importance of father and mother with regard to educational achievement of the child. Key words: Transnational educational strategies, cosmopolitan capital, cultural capital, migration, reconversion strategies, Bourdieu

Permafrost degradation risk zone assessment using simulation models

In this proof-of-concept study we focus on linking large scale climate and permafrost simulations to small scale engineering projects by bridging the gap between climate and permafrost sciences on the one hand and on the other technical recommendation for adaptation of planned infrastructures to climate change in a region generally underlain by permafrost. We present the current and future state of permafrost in Greenland as modelled numerically with the GIPL model driven by HIRHAM climate projections up to 2080. We develop a concept called Permafrost Thaw Potential (PTP), defined as the potential active layer increase due to climate warming and surface alterations. PTP is then used in a simple risk assessment procedure useful for engineering applications. The modelling shows that climate warming will result in continuing wide-spread permafrost warming and degradation in Greenland, in agreement with present observations. We provide examples of application of the risk zone assessment approach for the two towns of Sisimiut and Ilulissat, both classified with high PTP

Is a Minimum Wage an Appropriate Instrument for Redistribution?

We analyse the redistributional (dis)advantages of a minimum wage over income taxation in competitive labour markets without imposing assumptions on the (in)efficiency of labour rationing. Compared to a distributionally equivalent tax change, a minimum-wage increase raises involuntary unemployment, but also raises skill formation as some individuals avoid unemployment. A minimum wage is an appropriate instrument for redistribution if and only if the public revenue gains from additional skill formation outweigh both the public revenue losses from additional unemployment and the utility losses of inefficient labour rationing. We show that this critically depends on how labour rationing is distributed among workers. A necessary condition for the desirability of a minimum-wage increase is that the public revenue gains from higher skill formation outweigh the revenue losses from higher unemployment. We write this condition in terms of measurable sufficient statistics

Meloneis Gen. Nov., a New Epipsammic Genus of Rhaphoneidaceae (Bacillariophyceae)

The diatom family Rhaphoneidaceae is characterized by high generic diversity and low species diversity with most genera known to have long stratigraphic ranges. The genera within this family are neritic marine, and mostly epipsammic. A new modern and epipsammic genus, Meloneis gen. nov., is described herein and is compared to all genera within Rhaphoneidaceae and especially to Rhaphoneis Ehrenberg s.l. Within Meloneis three new species and one variety are distinguished and described herein: M. mimallis sp. nov., M. mimallis var. zephyria var. nov., M. akytos sp. nov., and M. gorgis sp. nov

Pathogenic variants of sphingomyelin synthase SMS2 disrupt lipid landscapes in the secretory pathway

Sphingomyelin is a dominant sphingolipid in mammalian cells. Its production in the trans-Golgi traps cholesterol synthesized in the ER to promote formation of a sphingomyelin/sterol gradient along the secretory pathway. This gradient marks a fundamental transition in physical membrane properties that help specify organelle identify and function. We previously identified mutations in sphingomyelin synthase SMS2 that cause osteoporosis and skeletal dysplasia. Here, we show that SMS2 variants linked to the most severe bone phenotypes retain full enzymatic activity but fail to leave the ER owing to a defective autonomous ER export signal. Cells harboring pathogenic SMS2 variants accumulate sphingomyelin in the ER and display a disrupted transbilayer sphingomyelin asymmetry. These aberrant sphingomyelin distributions also occur in patient-derived fibroblasts and are accompanied by imbalances in cholesterol organization, glycerophospholipid profiles, and lipid order in the secretory pathway. We postulate that pathogenic SMS2 variants undermine the capacity of osteogenic cells to uphold nonrandom lipid distributions that are critical for their bone forming activity.Peer reviewe

Selective autophagy maintains centrosome integrity and accurate mitosis by turnover of centriolar satellites

The centrosome is the master orchestrator of mitotic spindle formation and chromosome segregation in animal cells. Centrosome abnormalities are frequently observed in cancer, but little is known of their origin and about pathways affecting centrosome homeostasis. Here we show that autophagy preserves centrosome organization and stability through selective turnover of centriolar satellite components, a process we termed doryphagy. Autophagy targets the satellite organizer PCM1 by interacting with GABARAPs via a C-terminal LIR motif. Accordingly, autophagy deficiency results in accumulation of large abnormal centriolar satellites and a resultant dysregulation of centrosome composition. These alterations have critical impact on centrosome stability and lead to mitotic centrosome fragmentation and unbalanced chromosome segregation. Our findings identify doryphagy as an important centrosome-regulating pathway and bring mechanistic insights to the link between autophagy dysfunction and chromosomal instability. In addition, we highlight the vital role of centriolar satellites in maintaining centrosome integrity