591 research outputs found
Derivation and study of dynamical models of dislocation densities
In this paper, starting from the microscopic dynamics of isolated
dislocations, we explain how to derive formally mean field models for the
dynamics of dislocation densities. Essentially these models are tranport
equations, coupled with the equations of elasticity. Rigorous results of
existence of solutions are presented for some of these models and the main
ideas of the proofs are given
CIDOC2VEC: Extracting Information from Atomized CIDOC-CRM Humanities Knowledge Graphs
The development of the field of digital humanities in recent years has led to the increased use of knowledge graphs within the community. Many digital humanities projects tend to model their data based on CIDOC-CRM ontology, which offers a wide array of classes appropriate for storing humanities and cultural heritage data. The CIDOC-CRM ontology model leads to a knowledge graph structure in which many entities are often linked to each other through chains of relations, which means that relevant information often lies many hops away from their entities. In this paper, we present a method based on graph walks and text processing to extract entity information and provide semantically relevant embeddings. In the process, we were able to generate similarity recommendations as well as explore their underlying data structure. This approach was then demonstrated on the Sphaera Dataset which was modeled according to the CIDOC-CRM data structure
CorDeep and the Sacrobosco Dataset: Detection of Visual Elements in Historical Documents
Recent advances in object detection facilitated by deep learning have led to numerous solutions in a myriad of fields ranging from medical diagnosis to autonomous driving. However, historical research is yet to reap the benefits of such advances. This is generally due to the low number of large, coherent, and annotated datasets of historical documents, as well as the overwhelming focus on Optical Character Recognition to support the analysis of historical documents. In this paper, we highlight the importance of visual elements, in particular illustrations in historical documents, and offer a public multi-class historical visual element dataset based on the Sphaera corpus. Additionally, we train an image extraction model based on YOLO architecture and publish it through a publicly available web-service to detect and extract multi-class images from historical documents in an effort to bridge the gap between traditional and computational approaches in historical studies
The Network of Early Modern Printers and Its Impact on the Evolution of Scientific Knowledge: Automatic Detection of Awareness Relationships
This work describes a computational method for reconstructing clusters of social relationships among early modern printers and publishers, the most determinant agents for the process of transformation of scientific knowledge. The method is applied to a dataset retrieved from the Sphaera corpus, a collection of 359 editions of textbooks used at European universities and produced between the years 1472 and 1650. The method makes use of standard bibliographic data and fingerprints; social relationships are defined as “awareness relationships”. The historical background is constituted of the production and economic practices of early modern printers and publishers in the academic book market. The work concludes with empirically validating historical case studies, their historical interpretation, and suggestions for further improvements by utilizing machine learning technologies
Electrical field stimulation-induced excitatory responses of pulmonary artery rings from monocrotaline-induced pulmonary hypertensive rats: influence of the endothelium
Background: Nitric oxide-mediated endothelium-dependent relaxation is attenuated in pulmonary artery segments from monocrotaline (MCT)-induced pulmonary hypertensive rats. However, the influence of the endothelium on adrenergic neurotransmission in the rat pulmonary artery has not been investigated. The aim of the present study was to investigate the effect of the endothelium on electrical field stimulation (EFS)-induced excitatory responses of pulmonary artery segments from pulmonary hypertensive rats. Methods: Pulmonary hypertension was induced in rats with a single dose of monocrotaline (60 mg/kg) and 21 days later, arterial rings were set up for isometric tension recording. EFS-induced contractions were recorded in the presence or absence of drugs. Results: Electrical field stimulation (EFS) induced frequency-dependent contractions in artery segments from control rats and these contractions were not affected by removing the endothelium. L-NAME (10-4 M), a nonselective NO synthase inhibitor, but not 7-NI, a selective neuronal NO synthase inhibitor, potentiated EFS-induced contractions. In addition, L-NAME had no effect on EFS-induced contractions in artery segments without the endothelium indicating a role for endotheliumderived NO in modulating adrenergic neurotransmission in the pulmonary artery. EFS also induced frequency-dependent contractions of artery segments from pulmonary hypertensive rats. These contractions, expressed relative to KCl-induced contractions, were greater in artery segments from pulmonary hypertensive rats. L-NAME (10-4 M) potentiated EFS-induced contractions of artery segments from MCT-treated rats and did not discriminate between artery segments from control and MCT-treated rats. L-NAME potentiated noradrenaline-induced contractions in artery segments from both groups indicating that the effect of L-NAME was mediated post-junctionally. Conclusion: Monocrotaline-induced pulmonary hypertension is associated with enhanced contractile response to EFS In addition, the modulatory effect of endothelial nitric oxide is unaltered in artery segments from pulmonary hypertensive rats.Keywords: Monocrotaline, pulmonary artery, pulmonary hypertension, electrical field stimulaion, NO synthas
Study of the ternary system water/sodium hydroxide/hydrazine for the extraction of hydrazine
Re-Emerging Vaccine-Preventable Diseases in War-Affected Peoples of the Eastern Mediterranean Region\u2014An Update
For the past few decades, the Eastern Mediterranean Region has been one area of the world profoundly shaped by war and political instability. On-going conflict and destruction have left the region struggling with innumerable health concerns that have claimed the lives of many. Wars, and the chaos they leave behind, often provide the optimal conditions for the growth and re-emergence of communicable diseases. In this article, we highlight a few of the major re-emerging vaccine preventable diseases in four countries of the Eastern Mediterranean Region that are currently affected by war leading to a migration crisis: Iraq, South Sudan, Syria, and Yemen. We will also describe the impact these infections have had on patients, societies, and national health care services. This article also describes the efforts, both local and international, which have been made to address these crises, as well as future endeavors that can be done to contain and control further devastation left by these diseases
Compact Circularly Polarized Multiband Antennas for RFID Applications
This paper presents multiband circularly polarized (CP) antennas for
radio frequency identification (RFID). A coax-fed and a microstrip-line-fed antennas having optimized cross-slots in their patches are first
designed for dual-band CP operation. The microstrip-line-fed design is then modified, by incorporating a U-shaped slot in its partial ground
plane, to achieve additional operation band with a CP characteristic. Simulation and measured results of the presented designs are reported.
The measured results are in accordance with the computed ones. The compact size and CP property make these designs suitable for RFID
applications
An Ever-Expanding Humanities Knowledge Graph: The Sphaera Corpus at the Intersection of Humanities, Data Management, and Machine Learning
Methylation and Expression Analyses of the 7q Autism Susceptibility Locus Genes MEST, COPG2, and TSGA14 in Human and Anthropoid Primate Cortices
The autism susceptibility locus on human chromosome 7q32 contains the maternally imprinted MEST and the non-imprinted COPG2 and TSGA14 genes. Autism is a disorder of the ‘social brain’ that has been proposed to be due to an overbalance of paternally expressed genes. To study regulation of the 7q32 locus during anthropoid primate evolution, we analyzed the methylation and expression patterns of MEST, COPG2, and TSGA14 in human, chimpanzee, Old World monkey (baboon and rhesus macaque), and New World monkey (marmoset) cortices. In all human and anthropoid primate cortices, the MEST promoter was hemimethylated, as expected for a differentially methylated imprinting control region, whereas the COPG2 and TSGA14 promoters were completely demethylated, typical for transcriptionally active non-imprinted genes. The MEST gene also showed comparable mRNA expression levels in all analyzed species. In contrast, COPG2 expression was downregulated in the human cortex compared to chimpanzee, Old and New World monkeys. TSGA14 either showed no differential regulation in the human brain compared to chimpanzee and marmoset or a slight upregulation compared to baboon. The human-specific downregulation supports a role for COPG2 in the development of a ‘social brain’. Promoter methylation patterns appear to be more stable during evolution than gene expression patterns, suggesting that other mechanisms may be more important for inter-primate differences in gene expression
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