Revista Jurídica Digital UANDES
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CCPi-Regularisation toolkit for computed tomographic image reconstruction with proximal splitting algorithms
No full textIterative reconstruction algorithms are often needed to help solve ill-posed inverse problems in computed tomography (CT), especially cases when tomographic projection data are corrupt, noisy or angularly undersampled. Model-based iterative methods can be adapted to fit the measurement characteristics of the data (e.g. noise statistics) and expectations regarding the reconstructed object (e.g. morphology). The prior information is usually introduced in the form of a regulariser, making the inversion task well-posed. The CCPi-Regularisation toolkit provides a set of variational regularisers (denoisers) which can be embedded in a plug-and-play fashion into proximal splitting methods for image reconstruction. CCPi-RGL comes with algorithms that can satisfy various prior expectations of the reconstructed object, for example being piecewise-constant or piecewise-smooth in nature. The toolkit is written in C language and exploits parallelism with OpenMP directives and the CUDA API; and is wrapped for the Python and MATLAB environments. This paper introduces the toolkit and gives recommendations for selecting a suitable prior model.</p
Dog breeds are mere Victorian confections, neither pure nor ancient
No full textModern dog breeds were created in Victorian Britain. The evolution of the domestic dog goes back tens of thousands of years – however, the multiple forms we see today are just 150 years old. Before the Victorian era, there were different types of dog, but there were not that many, and they were largely defined by their function. They were like the colours of a rainbow: variations within each type, shading into each other at the margins. And many terms were used for the different dogs: breed, kind, race, sort, strain, type and variety
Investigating the relationship between formal and informal care: an application using panel data for people living together
No full textThere is limited evidence on the relationship between informal and formal care using panel data in a UK setting and focused specifically on people living together (co-residents). Using all 18 waves of the British Household Panel Survey (BHPS) (1991-2009), we analyse the effect of informal care given by co-residents on use of formal home care and health care services more generally. To account for endogeneity, we estimate models using random effects instrumental variable (REIV) regression using the number of daughters as a source of exogenous variation. We find that a 10% increase in the monthly provision of informal care hours decreases the probability of using home help (formal home care) by 1.02 percentage points (p<0.05); equivalent to a 15.62% relative reduction. This effect was larger for home help provided by the state compared (β=-0.117) to non-state home help (β= -0.044). These results provide evidence that significant increases in the supply of informal care would reduce the demand for home-help provision
The Fetish of Accuracy:Perspectives on Early Modern Time(s)
No full textEarly modern protagonists desired temporal accuracy but were unable to achieve it, we often read in historians’ studies. As a result, nobody cared about temporal precision in everyday life. In this article on early modern temporalities, I argue that historians have too often assumed a desire for accurate time and subjection to imprecision in the sixteenth century. This assumption relied on establishing the early modern period as ‘the other’, a foreign object of study, where accuracy of time measurement serves as a distancing device. Such approaches to early modern history may turn periodization itself into a language of temporal judgement and construction that hampers our understanding of sixteenth-century realities of time. The historiography’s fetish of accuracy, I argue, is more revelatory of modern conceptualizations of modernity than the temporalities of early modern protagonists. Nevertheless, it is important to stress that this viewpoint is not against approaching early modern sources with a set of present questions in mind. This article brings to the surface the implications of present questions and shows how accuracy has been made a yardstick for past societies and present cultural hegemonies
Correlating Blocking Temperatures with Relaxation Mechanisms in Monometallic Single-Molecule Magnets with High Energy Barriers (Ueff > 600 K)
No full textWe report an empirical correlation between the blocking temperature of large energy barrier SMMs and the relaxation time at the point where the Raman and Orbach relaxation mechanisms have the same rate; this supports the idea that the ability to retain magnetisation is controlled by the Raman relaxation process in these novel materials
Genome-wide association and transcriptome studies identify target genes and risk loci for breast cancer
No full textGenome-wide association studies (GWAS) have identified more than 170 breast cancer susceptibility loci. Here we hypothesize that some risk-associated variants might act in non-breast tissues, specifically adipose tissue and immune cells from blood and spleen. Using expression quantitative trait loci (eQTL) reported in these tissues, we identify 26 previously unreported, likely target genes of overall breast cancer risk variants, and 17 for estrogen receptor (ER)-negative breast cancer, several with a known immune function. We determine the directional effect of gene expression on disease risk measured based on single and multiple eQTL. In addition, using a gene-based test of association that considers eQTL from multiple tissues, we identify seven (and four) regions with variants associated with overall (and ER-negative) breast cancer risk, which were not reported in previous GWAS. Further investigation of the function of the implicated genes in breast and immune cells may provide insights into the etiology of breast cancer.</p
High–performance InGaZnO–based ReRAMs
No full textAmorphous indium–gallium–zinc oxide (IGZO) is one of the most promising oxide semiconductors for thin–film transistors and it has started to replace amorphous silicon in display drivers. However, attempts to use IGZO in resistive random–access memories (ReRAMs) are still scarce. This work investigates the bipolar resistive switching properties of crossbar–ReRAM devices based on IGZO thin film. Aluminium bottom electrode and two different top electrodes (i.e. Al and Ag) were tested in the devices. It was discovered that an oxygen plasma treatment on the bottom electrode could significantly improve the surface roughness of the bottom electrode, the on/off ratio, and the switching uniformity. After the oxygen plasma treatment, the endurance of ReRAMs were enhanced. The on/off current ratios reached ~104 and 105 within 100 endurance cycles for Al and Ag top electrode devices, respectively. Furthermore, the ReRAMs memory window remained nearly constant during a retention test of 105 s. The conduction mechanisms of the two device structures were examined using Schottky emission and space–charge–limited–current pictures, and the memory effect was explained by the formation and the interruption of filaments
Event-based Resilient Formation Control of Multi-Agent Systems
No full textThis paper focuses on the time-varying formation tracking issue for nonlinear multi-agent systems (MASs). Based on the explicit characterizations of frequency, duration and magnitude properties for deception attacks, a hybrid framework is proposed for time-varying formation tracking of nonlinear MASs. To realize the desired formation tracking performance under deception attacks, the distributed edge-based event triggered communication strategies are proposed with Zenofreeness. The designed strategies are resilient to deception attacks under some appropriate assumptions, to realize a predefined formation and simultaneously track the convex combination of leaders’ states. The designed control strategies render that we do not need to detect when the deception attack happens. Furthermore, the obtained results can be deduced to deal with consensus/synchronization problems, target enclosing problems for MASs with one/multiple leaders, where the communication is attacked by malicious attackers. An example of time-varying formation tracking of unmanned aerial vehicles is provided to show the effectiveness of the obtained results
Microstructure evolution during nano-emulsification by NMR and microscopy
No full textHypothesisMicrostructure evolution in emulsions as a function of composition is of great interest but fundamentals have not yet been fully elucidated. Here, pulsed-field gradient (PFG) NMR diffusion measurements have been combined with confocal laser scanning microscopy (CLSM) to assess evolution of dynamics and microstructure during nano-emulsification.ExperimentsDiffusion coefficients of emulsions made of water, mineral oil and surfactants (Span 20 and Tween 80) were measured as a function of water composition and compared with the morphological features of the emulsions obtained by CLSM.FindingsIn the absence of water, two phases are visible from CLSM, and two diffusion components are observed with PFG NMR, a major fast component attributed to a continuous oil phase containing the more hydrophobic surfactant Span 20 with traces of Tween 80, and a minor slow component attributed to a dispersed phase of the more hydrophilic surfactant Tween 80 with traces of mineral oil and Span 20. At the inversion point (25 wt% water) the two-component diffusion behavior of the oil-rich phase is drastically reversed in terms of populations, with the slow diffusion process becoming dominant. This suggests a significant structuring of the oil-rich phase in the presence of surfactants enhanced by water, which can be explained by the formation of aggregates in the oil phase as reverse micelles or of a lamellar structure, and ties in well with the rheological measurements
Language-general and language-specific phenomena in the acquisition of inflectional noun morphology: A cross-linguistic elicited-production study of Polish, Finnish and Estonian.
No full textThe aim of this large-scale, preregistered, cross-linguistic study was to mediate between theories of the acquisition of inflectional morphology, which lie along a continuum from rule-based to analogy-based. Across three morphologically rich languages (Polish, Finnish and Estonian), 120 children (mean age 48.32 months, SD=7.0m) completed an experimental, elicited-production study of noun case marking. Confirmatory analyses found effects of surface-form (whole-word, token) frequency for Polish and Estonian, and phonological neighbourhood density (PND) for all three languages (using either our preregistered class-based or an exploratory form-based measure). An exploratory all-languages analysis yielded both main effects, and a predicted interaction, such that the effect of PND was greater for forms with lower surface-form frequency, which are less available for direct retrieval from memory. Cross-linguistic differences were investigated with exploratory analyses of case variance, affix syncretism and stem changes. We conclude that these findings are difficult to reconcile with accounts that posit rules or linguistic abstractions and are most naturally explained by analogy-based connectionist or exemplar accounts