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This research investigates the application of plastic fiber reinforcement in pre-tensioned reinforced concrete railway sleepers, conducting an in-depth examination in both experimental and computational aspects. Utilizing 3-point bending tests and the GOM ARAMIS system for Digital Image Correlation, this study meticulously evaluates the structural responses and crack development in conventional and plastic fiber-reinforced sleepers under varying bending moments. Complementing these tests, the investigation employs ABAQUS' advanced finite element modeling to enhance the analysis, ensuring precise calibration and validation of the numerical models. This dual approach comprehensively explains the mechanical behavior differences and stresses within the examined structures. The incorporation of plastic fibers not only demonstrates a significant improvement in mechanical strength and crack resistance but paves the way for advancements in railway sleeper technology. By shedding light on the enhanced durability and performance of reinforced concrete structures, this study makes a significant contribution to civil engineering materials science, highlighting the potential for innovative material applications in the construction industry. [ABSTRACT FROM AUTHOR]

This paper focuses on the narrative aspect of Seneca's idea of self-transformation. It compares Seneca's viewpoint with some modern notions of the narrative self to highlight some parallels and significant differences between the ancient and modern conceptions and it establishes the reading of some parts of De Brev. Vit. in the context of other passages as concerned with the narrative self. The paper argues, amongst other points, that in Ep. 83.1–3, Seneca extends the practice of meditatio (ethically directed self-examination) by incorporating the construction of a narrative self into this process, in dual roles, as examiner and examined. It concludes that Seneca expected us to avail ourselves of a similar self-assessment based on a dialogue with philosophical texts. [ABSTRACT FROM AUTHOR]

Seneca's masterful application of metaphors often illuminates some Stoic technical terminology in contexts, which render them meaningful and familiar to his Roman readers. In this paper I argue that in certain instances, these metaphors are also used to organize whole systems of concepts that refer to an essential theoretical component of Seneca's philosophy. By studying the literary and philosophical context of these metaphors, I reconstruct Seneca's requirement for moral self-improvement in his Epistles and propose that his conception of conscientia or 'moral conscience'—a notion scattered throughout his writings but which, as the examination of his systematic metaphors will prove, has a consistent, identical function everywhere it appears—points to some novel rational characteristics of the philosopher's conception of the self. [ABSTRACT FROM AUTHOR]

This article summarizes the research results related to our own conducted extensive laboratory tests of polymer composite and steel fishplated glued insulated rail joints (GIRJs), namely axial tensile tests as well as vertical static and dynamic tests. The investigation dealt with the examination of GIRJs assembled with steel and special glass-fiber reinforced plastic (polymer composite) fishplates, both of them for CWR railway tracks (i.e. so-called gapless tracks or, in other words, railway tracks with continuously welded rails). The exact rail joint types were MTH-P and MTH-AP, consistently. The MTH P types have been commonly applied for many years in the CWR tracks in Europe, mainly in Hungary. The MTH-AP rail joints consist of fishplates that are produced by the APATECH factory (Russia). They are made of a fiberglassamplified polymer composite material at high pressure and controlled temperature. This solution can eliminate electrical fishplate lock and early fatigue failures just as it can ensure adequate electrical insulation. The advantage of such rail joints can be that they are probably able to ensure the substitution of the glued insulated rail joints with relatively expensive steel fishplates currently applied by railway companies, e.g. Hungarian State Railways (MÁV). The aim of the mentioned research summarized in this paper is to formulate recommendations on technical applicability and on the technological instructions that are useful in everyday railway operation practice on the basis of the measurements and tests carried out on rail joints in laboratory. [ABSTRACT FROM AUTHOR]

The current state‐of‐the‐art analysis of central nervous system (CNS) tumors through DNA methylation profiling relies on the tumor classifier developed by Capper and colleagues, which centrally harnesses DNA methylation data provided by users. Here, we present a distributed‐computing‐based approach for CNS tumor classification that achieves a comparable performance to centralized systems while safeguarding privacy. We utilize the t‐distributed neighborhood embedding (t‐SNE) model for dimensionality reduction and visualization of tumor classification results in two‐dimensional graphs in a distributed approach across multiple sites (DistSNE). DistSNE provides an intuitive web interface (https://gin-tsne.med.uni-giessen.de) for user‐friendly local data management and federated methylome‐based tumor classification calculations for multiple collaborators in a DataSHIELD environment. The freely accessible web interface supports convenient data upload, result review, and summary report generation. Importantly, increasing sample size as achieved through distributed access to additional datasets allows DistSNE to improve cluster analysis and enhance predictive power. Collectively, DistSNE enables a simple and fast classification of CNS tumors using large‐scale methylation data from distributed sources, while maintaining the privacy and allowing easy and flexible network expansion to other institutes. This approach holds great potential for advancing human brain tumor classification and fostering collaborative precision medicine in neuro‐oncology. [ABSTRACT FROM AUTHOR]

[Display omitted] • Molecular systematic revision of all but three European Nannospalax taxa. • Evolutionary history of Nannospalax (superspecies leucodon) sensu lato. • Statistical species delimitation helps to define species limits. • Three superspecies, 11 species and several additional subspecies recognised. Species delimitation is a powerful approach to assist taxonomic decisions in challenging taxa where species boundaries are hard to establish. European taxa of the blind mole rats (genus Nannospalax) display small morphological differences and complex chromosomal evolution at a shallow evolutionary divergence level. Previous analyses led to the recognition of 25 'forms' in their distribution area. We provide a comprehensive framework to improve knowledge on the evolutionary history and revise the taxonomy of European blind mole rats based on samples from all but three of the 25 forms. We sequenced two nuclear-encoded genetic regions and the whole mitochondrial cytochrome b gene for phylogenetic tree reconstructions using concatenation and coalescence-based species-tree estimations. The phylogenetic analyses confirmed that Aegean N. insularis belongs to N. superspecies xanthodon , and that it represents the second known species of this superspecies in Europe. Mainland taxa reached Europe from Asia Minor in two colonisation events corresponding to two superspecies-level taxa: N. superspecies monticola (taxon established herewith) reached Europe c. 2.1 million years ago (Mya) and was followed by N. superspecies leucodon (re-defined herewith) c. 1.5 Mya. Species delimitation allowed the clarification of the taxonomic contents of the above superspecies. N. superspecies monticola contains three species geographically confined to the western periphery of the distribution of blind mole rats, whereas N. superspecies leucodon is more speciose with six species and several additional subspecies. The observed geographic pattern hints at a robust peripatric speciation process and rapid chromosomal evolution. The present treatment is thus regarded as the minimum taxonomic content of each lineage, which can be further refined based on other sources of information such as karyological traits, crossbreeding experiments, etc. The species delimitation models also allowed the recognition of a hitherto unnamed blind mole rat taxon from Albania, described here as a new subspecies. [ABSTRACT FROM AUTHOR]

A new population of blind mole rat (genus Nannospalax) was discovered near the town of Albertirsa in north-central Hungary. We used newly designed primers to specifically amplify the whole mitochondrial cytochrome-b region and two nuclear DNA regions. Based on the most comprehensive taxonomic sampling to date, we compared this population with several other European blind mole-rat taxa. The results from both mitochondrial and nuclear regions have unequivocally placed the Albertirsa population into the monophyletic group of the Vojvodina blind mole rat (N. (leucodon) montanosyrmiensis), which turned out to be a sister clade to all other molecularly studied European Nannospalax. This study not only identified the fourth known population of an extremely rare rodent taxon but also calls for a taxonomic revision of European lesser blind mole rats (N. leucodon superspecies) to systematically evaluate the genetic structure of their populations and to understand the complex evolutionary history of these European rodents. The occurrence of the Vojvodina blind mole rat at this northern location helps to clarify the distribution area of this heavily data-deficient taxon. As currently understood, this lineage predominantly occurs in sandy grasslands of the Danube-Tisza Interfluve in Hungary and Serbia. Its distribution range and phylogenetic structure might reflect the importance of potential biogeographical barriers (e.g. large rivers) that shaped the blind mole rats' allopatric or peripatric speciation. [ABSTRACT FROM AUTHOR]

The nucleolus is the largest nuclear sub-compartment in which the early steps of ribosome biogenesis take place. It also plays an essential role in the assembly and function of non-ribosomal ribonucleoprotein (RNP) complexes, controls cell cycle progression and senses environmental stress. The spatial organization and dynamics of nucleolar proteins and RNA is regulated at different structural levels, which finally determine nucleolar architecture. The intimate link between nucleolar structure and function is reflected by transcription-dependent changes in nucleolus-associated chromatin, overall morphological alterations in response to external cues, and the liquid droplet-like behavior of nucleolar compartments. Here we provide a concise overview of the latest studies which integrate novel trends in nucleolar architecture research into the context of cell biology. [ABSTRACT FROM AUTHOR]

Mammals are a key target group for conservation biology. Insights into the patterns and timing of and driving forces behind their past extinctions help us to understand their present, and to predict and mitigate their future biodiversity loss. Much research has been focused on the intensely debated megafaunal extinctions at the Pleistocene-Holocene transition, whereas the Holocene mammal extinctions have remained less studied., Here, we consider the Holocene extinctions of mammal taxa in the Carpathian Basin, a distinctive and biogeographically well-constrained predominantly lowland region in Central Europe. For the first time, we combine data from palaeontological, archaeozoological, and historical sources for a comprehensive analysis., A total of 11 mammal species, including steppe-dwelling rodents, large carnivores and herbivores, disappeared from the Carpathian Basin during the Holocene. The extinctions are interpreted in the framework of changing habitats and ecosystems, as grasslands and open forests vanished at the westernmost limits of the Eurasian steppe., The temporal distribution of extinctions is non-random; most taxon range terminations are concentrated around two discrete events. Members of the steppe community disappeared between 5000 and 4000 BP, around the Copper Age-Bronze Age transition. Large herbivores that found refugia in the forests vanished later, between the 16th and 18th centuries AD. The steppe, forest-steppe ecosystems of the Carpathian Basin suffered a considerable loss in their mammalian fauna, which has significant implications for conservation efforts for the existing similar dry, open habitats in western Eurasia., Further research and better age constraints are needed to establish the causes of extinctions more firmly, but the lack of synchronous and severe climate and vegetation changes and the coincidence with transformations in human history suggest the prime role of anthropogenic disturbance. We conclude that there were two waves of Holocene mammal extinctions of megafaunal character in the Carpathian Basin. [ABSTRACT FROM AUTHOR]

Ion implantation has been a key technology for the controlled surface modification of materials in microelectronics and generally, for tribology, biocompatibility, corrosion resistance and many more. To form shallow junctions in Ge is a challenging task. In this work the formation and accumulation of shallow damage profiles was studied by in-situ spectroscopic ellipsometry (SE) for the accurate tracking and evaluation of void and damage fractions in crystalline Ge during implantation of 200-keV Sb + ions with a total fluence up to 1016 cm−2 and an ion flux of 2.1 × 1012 cm−2s−1. The consecutive stages of damage accumulation were identified using optical multi-layer models with quantitative parameters of the thickness of modified layers as well as the volume fractions of amorphized material and voids. The effective size of damaged zones formed from ion tracks initiated by individual bombarding ions can be estimated by numerical simulation compared with the dynamics of damage profiles measured by ion beam analysis and ellipsometry. According to our observations, the formation of initial partial disorder was followed by complete amorphization and void formation occurring at the fluence of about 1 × 1015 cm−2, leading to a high volume fraction of voids and a modified layer thickness of ≈200 nm by the end of the irradiation process. This agrees with the results of numerical simulations and complementary scanning electron microscopy (SEM) measurements. In addition, we found a quasi-periodic time dependent behavior of amorphization and void formation represented by alternating accelerations and decelerations of different reorganization processes, respectively. For the understanding and prevention of adverse void formation and for controlled evolution of subsurface nanocavities or cellular surface texture the in-situ monitoring of the dynamics of structural damage accumulation by the developed SE method is essential. [ABSTRACT FROM AUTHOR]

Being totally blind with no tail or pinnae, blind mole rats are the most specialised rodents for the subterranean lifestyle. However, they come to the surface occasionally due to unusual climatic events, for foraging, to collect hay for bedding material, for dispersal as subadults, due to intraspecific aggression, and in illness., The only previous review suggests that surface activity of and predation on blind mole rats is rare and that they are preyed on mainly at night by owls., Based on 57 scientific publications, 14 unpublished reports and several personal observations (from 15 countries), the present review reveals that altogether 26 species of bird and mammal prey on blind mole rats either regularly or occasionally. It is evidenced that not only the number of predators, but also the importance of blind mole rats in their diet has been seriously underestimated., The tight relationship between the colour of the soil and the colour of the pelage of blind mole rats suggests the importance of diurnal raptors via their selective impact. Predation by mammals happens relatively often, and mustelids hunt blind mole rats not only on the surface, but probably also inside their burrows. The labyrinth-like structure of the burrows may play a vital role in confusing mammalian predators trying to hunt inside the burrows, and may increase the blind mole rat's chance of escape., With the proven importance of blind mole rats as a food resource for several threatened species of birds of prey, the survival, reproductive success, and population size of these species may partly depend on the density of the rodents. Although many species within the blind mole rat subfamily are themselves threatened to various extents, the role of blind mole rat populations in carnivore and raptor conservation should be considered and evaluated. [ABSTRACT FROM AUTHOR]

This article explores the distribution and composition of the ferritin complex in the adult brain and its connection to neuroferritinopathy (NF), a type of neurodegeneration with brain iron accumulation (NBIA). NF is characterized by symptoms like movement disturbances and tremors. The study identifies a novel variant in the ferritin heavy chain gene (FTH1) that is associated with NF and provides insights into the role of ferritin in both healthy and diseased brains. The authors, a diverse group of researchers, present their findings in a respectful and culturally sensitive manner, making this report a valuable resource for library patrons researching this topic. [Extracted from the article]

The nucleolus, the largest subcompartment of the nucleus, stands out from the nucleoplasm due to its exceptionally high local RNA and low DNA concentrations. Within this central hub of nuclear RNA metabolism, ribosome biogenesis is the most prominent ribonucleoprotein (RNP) biogenesis process, critically determining the structure and function of the nucleolus. However, recent studies have shed light on other roles of the nucleolus, exploring the interplay with various noncoding RNAs that are not directly involved in ribosome synthesis. This review focuses on this intriguing topic and summarizes the techniques to study and the latest findings on nucleolar long noncoding RNAs (lncRNAs) as well as microRNAs (miRNAs) in the context of nucleolus biology beyond ribosome biogenesis. We particularly focus on the multifaceted roles of the nucleolus and noncoding RNAs in physiology and tumor biology. [ABSTRACT FROM AUTHOR]

Simple Summary: Meningioma is the most common primary intracranial tumor. DNA methylation-based subtyping, while highly useful for diagnosis and treatment planning, is costly and not widely available. Therefore, the identification of methylation classes based on histological sections would be highly beneficial as it could greatly support and accelerate diagnostic and treatment decisions. We developed and systematically evaluated an AI framework to perform the classification of the most prevalent methylation subtypes based on histological sections. The model achieved a balanced accuracy of 0.870 for benign-1 vs benign-2 and 0.749 for benign-1 vs. intermediate-A in a narrow validation set. Combined with the network's assessed focus on key tumor regions these results provide a promising proof-of-concept of such an AI-driven classification approach in precision medicine. Convolutional neural networks (CNNs) are becoming increasingly valuable tools for advanced computational histopathology, promoting precision medicine through exceptional visual decoding abilities. Meningiomas, the most prevalent primary intracranial tumors, necessitate accurate grading and classification for informed clinical decision-making. Recently, DNA methylation-based molecular classification of meningiomas has proven to be more effective in predicting tumor recurrence than traditional histopathological methods. However, DNA methylation profiling is expensive, labor-intensive, and not widely accessible. Consequently, a digital histology-based prediction of DNA methylation classes would be advantageous, complementing molecular classification. In this study, we developed and rigorously assessed an attention-based multiple-instance deep neural network for predicting meningioma methylation classes using tumor methylome data from 142 (+51) patients and corresponding hematoxylin-eosin-stained histological sections. Pairwise analysis of sample cohorts from three meningioma methylation classes demonstrated high accuracy in two combinations. The performance of our approach was validated using an independent set of 51 meningioma patient samples. Importantly, attention map visualization revealed that the algorithm primarily focuses on tumor regions deemed significant by neuropathologists, offering insights into the decision-making process of the CNN. Our findings highlight the capacity of CNNs to effectively harness phenotypic information from histological sections through computerized images for precision medicine. Notably, this study is the first demonstration of predicting clinically relevant DNA methylome information using computer vision applied to standard histopathology. The introduced AI framework holds great potential in supporting, augmenting, and expediting meningioma classification in the future. [ABSTRACT FROM AUTHOR]

Background: Bipolar disorder if untreated, has severe consequences: severe role impairment, higher health care costs, mortality and morbidity. Although effective treatment is available, the delay in diagnosis might be as long as 10–15 years. In this study, we aim at documenting the length of the diagnostic delay in Hungary and identifying factors associated with it. Methods: Kaplan-Meier survival analysis and Cox proportional hazards model was employed to examine factors associated with the time to diagnosis of bipolar disorder measured from the date of the first presentation to any specialist mental healthcare institution. We investigated three types of factors associated with delays to diagnosis: demographic characteristics, clinical predictors and patient pathways (temporal sequence of key clinical milestones). Administrative data were retrieved from specialist care; the population-based cohort includes 8935 patients from Hungary. Results: In the sample, diagnostic delay was 6.46 years on average. The mean age of patients at the time of the first bipolar diagnosis was 43.59 years. 11.85% of patients were diagnosed with bipolar disorder without any delay, and slightly more than one-third of the patients (35.10%) were never hospitalized with mental health problems. 88.80% of the patients contacted psychiatric care for the first time in outpatient settings, while 11% in inpatient care. Diagnostic delay was shorter, if patients were diagnosed with bipolar disorder by non-specialist mental health professionals before. In contrast, diagnoses of many psychiatric disorders received after the first contact were coupled with a delayed bipolar diagnosis. We found empirical evidence that in both outpatient and inpatient care prior diagnoses of schizophrenia, unipolar depression without psychotic symptoms, and several disorders of adult personality were associated with increased diagnostic delay. Patient pathways played an important role as well: the hazard of delayed diagnosis increased if patients consulted mental healthcare specialists in outpatient care first or they were hospitalized. Conclusions: We systematically described and analysed the diagnosis of bipolar patients in Hungary controlling for possible confounders. Our focus was more on clinical variables as opposed to factors controllable by policy-makers. To formulate policy-relevant recommendations, a more detailed analysis of care pathways and continuity is needed. [ABSTRACT FROM AUTHOR]

Mammalian chromosomes are organized in structural and functional domains of 0.1–10 Mb, which are characterized by high self-association frequencies in the nuclear space and different contact probabilities with nuclear sub-compartments. They exhibit distinct chromatin modification patterns, gene expression levels and replication timing. Recently, nucleolus-associated chromosomal domains (NADs) have been discovered, yet their precise genomic organization and dynamics are still largely unknown. Here, we use nucleolus genomics and single-cell experiments to address these questions in human embryonic fibroblasts during replicative senescence. Genome-wide mapping reveals 1,646 NADs in proliferating cells, which cover about 38% of the annotated human genome. They are mainly heterochromatic and correlate with late replicating loci. Using Hi-C data analysis, we show that interactions of NADs dominate interphase chromosome contacts in the 10–50 Mb distance range. Interestingly, only minute changes in nucleolar association are observed upon senescence. These spatial rearrangements in subdomains smaller than 100 kb are accompanied with local transcriptional changes. In contrast, large centromeric and pericentromeric satellite repeat clusters extensively dissociate from nucleoli in senescent cells. Accordingly, H3K9me3-marked heterochromatin gets remodelled at the perinucleolar space as revealed by immunofluorescence analyses. Collectively, this study identifies connections between the nucleolus, 3D genome structure, and cellular aging at the level of interphase chromosome organization. [ABSTRACT FROM AUTHOR]

Ribosomal RNA (rRNA) transcription by RNA polymerase I (Pol I) is the first key step of ribosome biogenesis. While the molecular mechanisms of rRNA transcription regulation have been elucidated in great detail, the functional organization of the multicopy rRNA gene clusters (rDNA) in the nucleolus is less well understood. Here we apply super-resolution 3D structured illumination microscopy (3D-SIM) to investigate the spatial organization of transcriptionally competent active rDNA chromatin at size scales well below the diffraction limit by optical microscopy. We identify active rDNA chromatin units exhibiting uniformly ring-shaped conformations with diameters of ~240 nm in mouse and ~170 nm in human fibroblasts, consistent with rDNA looping. The active rDNA chromatin units are clearly separated from each other and from the surrounding areas of rRNA processing. Simultaneous imaging of all active genes bound by Pol I and the architectural chromatin protein Upstream Binding Transcription Factor (UBF) reveals a random spatial orientation of regular repeats of rDNA coding sequences within the nucleoli. These observations imply rDNA looping and exclude potential formation of systematic spatial assemblies of the well-ordered repetitive arrays of transcription units. Collectively, this study uncovers key features of the 3D organization of active rDNA chromatin units and their nucleolar clusters providing a spatial framework of nucleolar chromatin organization at unprecedented detail. [ABSTRACT FROM AUTHOR]

The nucleolus is the site of ribosome biogenesis and forms around the actively transcribed ribosomal RNA (rRNA) genes. However, the nucleolus is also implicated in cell cycle regulation, tumour suppression and chromosome segregation and nucleolar disfunction is linked to a wide range of human diseases. Interestingly, the nucleolus is also required for genome reprogramming and the establishment of heterochromatin in the mammalian embryo. Mammalian oocytes contain a subnuclear structure that is believed to be the precursor of the functional nucleolus, the Nucleolar Precursor Body (NPB). But the NPB is also required for the organisation of the zygotic heterochromatin and the establishment of pluripotency. We found that disruption of the mouse Upstream Binding Factor (UBF (UBTF)) gene caused disassembly of somatic nucleoli and the accumulation of the key rRNA gene transcription factors into dense subnuclear foci resembling NPBs. Here we show that UBF deletion causes the rRNA genes to collapse onto their centromere-proximal chromosomal sites spatially distinct from NPB-like structures, and that these structures contain rRNA gene transcription factors but not all nucleolar proteins. We further find that embryonic NPBs and their surrounding heterochromatin are both disrupted in UBF-null mouse embryos. These embryos also display subnuclear foci containing the rRNA gene transcription factors and arrest development before completing the forth cleavage division. The data suggest that the rRNA gene transcription factors have an intrinsic ability to interact and form a discrete nuclear compartment even in the absence of any rRNA gene activity and that the formation or maintenance of the zygotic NPB and surrounding heterochromatin requires UBF. [ABSTRACT FROM AUTHOR]

Non-coding RNAs play a key role in organizing the nucleus into functional subcompartments. By combining fluorescence microscopy and RNA deep-sequencing-based analysis, we found that RNA polymerase II transcripts originating from intronic Alu elements (aluRNAs) were enriched in the nucleolus. Antisense-oligo-mediated depletion of aluRNAs or drug-induced inhibition of RNA polymerase II activity disrupted nucleolar structure and impaired RNA polymerase I-dependent transcription of rRNA genes. In contrast, over-expression of a prototypic aluRNA sequence increased both nucleolus size and levels of pre-rRNA, suggesting a functional link between aluRNA, nucleolus integrity and pre-rRNA synthesis. Furthermore, we show that aluRNAs interact with nucleolin and target ectopic genomic loci to the nucleolus. Our study suggests an aluRNA-based mechanism that links RNA polymerase I and II activities and modulates nucleolar structure and rRNA production. [ABSTRACT FROM AUTHOR]

Upstream Binding Factor (UBF) is a unique multi-HMGB-box protein first identified as a co-factor in RNA polymerase I (RPI/PolI) transcription. However, its poor DNA sequence selectivity and its ability to generate nucleosome-like nucleoprotein complexes suggest a more generalized role in chromatin structure. We previously showed that extensive depletion of UBF reduced the number of actively transcribed ribosomal RNA (rRNA) genes, but had little effect on rRNA synthesis rates or cell proliferation, leaving open the question of its requirement for RPI transcription. Using gene deletion in mouse, we now show that UBF is essential for embryo development beyond morula. Conditional deletion in cell cultures reveals that UBF is also essential for transcription of the rRNA genes and that it defines the active chromatin conformation of both gene and enhancer sequences. Loss of UBF prevents formation of the SL1/TIF1B pre-initiation complex and recruitment of the RPI-Rrn3/TIF1A complex. It is also accompanied by recruitment of H3K9me3, canonical histone H1 and HP1α, but not by de novo DNA methylation. Further, genes retain penta-acetyl H4 and H2A.Z, suggesting that even in the absence of UBF the rRNA genes can maintain a potentially active state. In contrast to canonical histone H1, binding of H1.4 is dependent on UBF, strongly suggesting that it plays a positive role in gene activity. Unexpectedly, arrest of rRNA synthesis does not suppress transcription of the 5S, tRNA or snRNA genes, nor expression of the several hundred mRNA genes implicated in ribosome biogenesis. Thus, rRNA gene activity does not coordinate global gene expression for ribosome biogenesis. Loss of UBF also unexpectedly induced the formation in cells of a large sub-nuclear structure resembling the nucleolar precursor body (NPB) of oocytes and early embryos. These somatic NPBs contain rRNA synthesis and processing factors but do not associate with the rRNA gene loci (NORs). [ABSTRACT FROM AUTHOR]

The good control of the n -type doping is a key issue for the fabrication of efficient devices based on ε-Ga 2 O 3 epilayers. In this work we studied the possibility of doping the ε-Ga 2 O 3 thin films, epitaxially grown on c -oriented sapphire by metal-organic chemical vapor deposition, by means of a post-deposition treatment. For the first time, the n -type doping was achieved by depositing a tin-rich SnO 2 film on top of the ε-Ga 2 O 3 layer and keeping this bi-layer system for 4 h at a temperature of 600 °C in an evacuated furnace. The diffusion of Sn atoms into the ε-Ga 2 O 3 film is evidenced by time-of-flight secondary-ion mass spectrometry depth profiles. Room-temperature resistivity of the order of 1 Ω•cm is obtained and the electrical characterization revealed a conduction mechanism based on variable range hopping, according to the Mott's model. [Display omitted] [ABSTRACT FROM AUTHOR]

The multilayer of approximate structure MgO(100)/[nFe51Rh49(63 Å)/57Fe51Rh49(46 Å)]10 deposited at 200 °C is primarily of paramagnetic A1 phase and is fully converted to the magnetic B2 phase by annealing at 300 °C for 60 min. Subsequent irradiation by 120 keV Ne+ ions turns the thin film completely to the paramagnetic A1 phase. Repeated annealing at 300 °C for 60 min results in 100% magnetic B2 phase, i.e. a process that appears to be reversible at least twice. The A1 → B2 transformation takes place without any plane-perpendicular diffusion while Ne+ irradiation results in significant interlayer mixing. [ABSTRACT FROM AUTHOR]