Glioblastomas with primitive neuronal component harbor a distinct methylation and copy‑number profle with inactivation of TP53, PTEN, and RB1

Glioblastoma IDH-wildtype presents with a wide histological spectrum. Some features are so distinctive that they are considered as separate histological variants or patterns for the purpose of classification. However, these usually lack defined (epi-)genetic alterations or profiles correlating with this histology. Here, we describe a molecular subtype with overlap to the unique histological pattern of glioblastoma with primitive neuronal component. Our cohort consists of 63 IDH-wildtype glioblastomas that harbor a characteristic DNA methylation profile. Median age at diagnosis was 59.5 years. Copy-number variations and genetic sequencing revealed frequent alterations in TP53, RB1 and PTEN, with fewer gains of chromosome 7 and homozygous CDKN2A/B deletions than usually described for IDH-wildtype glioblastoma. Gains of chromosome 1 were detected in more than half of the cases. A poorly differentiated phenotype with frequent absence of GFAP expression, high proliferation index and strong staining for p53 and TTF1 often caused misleading histological classification as carcinoma metastasis or primitive neuroectodermal tumor. Clinically, many patients presented with leptomeningeal dissemination and spinal metastasis. Outcome was poor with a median overall survival of only 12 months. Overall, we describe a new molecular subtype of IDH-wildtype glioblastoma with a distinct histological appearance and genetic signature.publishedVersio

Phase transitions in quantum chromodynamics

The current understanding of finite temperature phase transitions in QCD is reviewed. A critical discussion of refined phase transition criteria in numerical lattice simulations and of analytical tools going beyond the mean-field level in effective continuum models for QCD is presented. Theoretical predictions about the order of the transitions are compared with possible experimental manifestations in heavy-ion collisions. Various places in phenomenological descriptions are pointed out, where more reliable data for QCD's equation of state would help in selecting the most realistic scenario among those proposed. Unanswered questions are raised about the relevance of calculations which assume thermodynamic equilibrium. Promising new approaches to implement nonequilibrium aspects in the thermodynamics of heavy-ion collisions are described.Comment: 156 pages, RevTex. Tables II,VIII,IX and Fig.s 1-38 are not included as postscript files. I would like to ask the requestors to copy the missing tables and figures from the corresponding journal-referenc

Historical Missionary Activity, Schooling, and the Reversal of Fortunes: Evidence from Nigeria

This paper shows that historical missionary activity has had a persistent effect on schooling outcomes, and contributed to a reversal of fortunes wherein historically richer ethnic groups are poorer today. Combining contemporary individual-level data with a newly constructed dataset on mission stations in Nigeria, we find that individuals whose ancestors were exposed to greater missionary activity have higher levels of schooling. This effect is robust to omitted heterogeneity, ethnicity fixed effects, and reverse causation. We find inter-generational factors and the persistence of early advantages in educational infrastructure to be key channels through which the effect has persisted. Consistent with theory, the effect of missions on current schooling is larger for population subgroups that have historically suffered disadvantages in access to education

Missions, education and conversion in Colonial Africa

This chapter traces the origins and long-term development of African mass education in colonial sub-Saharan Africa. Specifically, it addresses the unique role of Christian missions in prompting a genuine schooling revolution and explores the comparative educational expansion across colonies and between genders. While the initial expansion of missions was motivated by a global competition for new church members, the development of African mass education essentially depended on local conditions. It highlights the importance of African agency in the process toward mass education that depended on local demand for formal education and the supply of African teachers who provided the bulk of mission schooling. The chapter also assesses potential pitfalls when those realities are not considered by studies, investigating historical missionary legacies on present-day African education and social mobility

Electroplane, un projet innovant

Description d'une construction prototype d'un planeur motorisé avec un moteur électrique : solutions techniques (cellule, moteur, batteries), état actuel du projet. Encart : l'énergie nécessaire pour monter à 800m une machine de 240 kg, en six minutes

The origin and characterization of conformational heterogeneity in adsorbed polymer layers

The equilibration of polymer conformations tends to be sluggish in polymer layers adsorbed onto highly attractive substrates, so the structure of these layers must be understood in terms of the layer growth process rather than equilibrium theory. Initially adsorbed chains adopt a highly Battened configuration while the chains which arrive later must adapt their configurations to the increasingly limited space available for adsorption. Thus, the chains adsorbed in the late stage of deposition are more tenuously attached to the surface. This type of non-equilibrium growth process is studied for polymethylmethacrylate (PMMA) adsorbed on oxidized silicon where the segmental attraction is strong (4 k(B) T/segment) and for polystyrene (PS) adsorbed on oxidized silicon from a carbon tetrachloride solution where the segmental attraction is relatively weak (1 k(B)T/segment). Measurements were based on Fourier transform infrared spectroscopy in attenuated total reflection (FTIR-ATR). In both cases, the chains arriving first adsorbed more tightly, became flattened (as measured by the dichroic ratio), and occupied a disproportionately large fraction of the surface. This non-uniform structure persisted indefinitely for the strongly adsorbed PMMA chains, while the PS chains exhibited a gradual evolution, presumably reflecting an equilibration of the adsorbed layer occurring after long times. On the theoretical side, the initial heterogeneity of these adsorbed polymer layers is modelled using a random sequential adsorption (RSA) model where the size of the adsorbing species is allowed to adapt to the surface space available at the time of adsorption. The inhomogeneity in the size of adsorbing species (hemispheres) in this model is similar to the distribution of chain contacts in our measurements on adsorbed polymer layers. Owing to extensive variance around the mean, conformations having the mean number of chain contacts are least probable, which contrasts starkly with expectations based on equilibrium adsorption theory