1,754 research outputs found

    A computationally and cognitively plausible model of supervised and unsupervised learning

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    Author version made available in accordance with the publisher's policy. "The final publication is available at link.springer.com”The issue of chance correction has been discussed for many decades in the context of statistics, psychology and machine learning, with multiple measures being shown to have desirable properties, including various definitions of Kappa or Correlation, and the psychologically validated ΔP measures. In this paper, we discuss the relationships between these measures, showing that they form part of a single family of measures, and that using an appropriate measure can positively impact learning

    Comparison between three-dimensional linear and nonlinear tsunami generation models

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    The modeling of tsunami generation is an essential phase in understanding tsunamis. For tsunamis generated by underwater earthquakes, it involves the modeling of the sea bottom motion as well as the resulting motion of the water above it. A comparison between various models for three-dimensional water motion, ranging from linear theory to fully nonlinear theory, is performed. It is found that for most events the linear theory is sufficient. However, in some cases, more sophisticated theories are needed. Moreover, it is shown that the passive approach in which the seafloor deformation is simply translated to the ocean surface is not always equivalent to the active approach in which the bottom motion is taken into account, even if the deformation is supposed to be instantaneous.Comment: 39 pages, 16 figures; Accepted to Theoretical and Computational Fluid Dynamics. Several references have been adde

    User-Centered Evaluation of a Discovery Layer System with Google Scholar

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    Discovery layer systems allow library users to obtain search results from multiple library resources and view results in a consistent format. The implementation of a discovery layer is expected to simplify users’ workflow of searching for scholarly information. Previous studies on discovery layer systems focused on functionality and content, but not quality of search results from the user’s perspective. The objective of this study was to obtain users’ assessment of search results of a discovery layer system (Ex Libris Primo®) and compare that with a widely used scholarly search tool (Google Scholar). Results showed that Primo’s search results relevancy is comparable to Google Scholar, but it received significantly lower usability and preference ratings. A number of usability issues of Primo were also identified from the study. Results of the study are used to improve the interface of Primo and adjust relevancy ranking options. The empirical method of search results assessment and feedback collection used in this study can be extended to similar user-centered system implementation and evaluation efforts

    Riječ akademika Josipa Torbarine, tajnika Razreda za filologiju JAZU

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    Physical ocean processes (ice-melt, island run-off and upwelling of nutrients) were hypothesised to affect the bacterioplankton composition in the surface mixed layer of the Scotia Sea during the austral summer of 2003, and this was investigated using flow cytometry and catalysed reporter deposition fluorescence in situ hybridisation (CARD-FISH) techniques. The bacterioplankton was composed predominantly of Alphaproteobacteria (PB), comprising SAR11, Roseobacterspp. and SAR116 groups, followed by Sphingobacteria/Flavobacteria and Gammaproteobacteria, including SAR86. Two distinct bacterioplankton communities were identified, largely based on bacterioplankton abundance, which varied from 0.3 ± 0.06 × 106 cells ml–1 in the west to 0.8 ± 0.3 × 106 cells ml–1 in the east, and a corresponding difference in SAR11 percentages of 30 ± 15% in the west compared to 5 ± 5% in the east. The western community was present in waters that were largely in an over-wintered, pre-bloom condition. The eastern bacterioplankton community was associated with phytoplankton blooms developed within the eastern Scotia Sea nutrient upwelling zone, where the Antarctic Circumpolar Current (ACC) encounters the shallow bathymetry associated with the Scotia Arc, in combination with seasonal ice-melt and island effects that enabled surface water stratification

    Integral field spectroscopy of massive young stellar objects in the N113 H II region in the Large Magellanic Cloud

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    The Spitzer Surveying the Agents of Galaxy Evolution (SAGE) survey has allowed the identification and analysis of significant samples of Young Stellar Object (YSO) candidates in the Large Magellanic Cloud (LMC). However, the angular resolution of Spitzer is relatively poor meaning that at the distance of the LMC, it is likely that many of the Spitzer YSO candidates in fact contain multiple components. We present high-resolution K-band integral field spectroscopic observations of the three most prominent massive YSO candidates in the N113 H?II region using Very Large Telescope/Spectrograph for INtegral Field Observations in the Near Infrared (VLT/SINFONI). We have identified six K-band continuum sources within the three Spitzer sources and we have mapped the morphology and velocity fields of extended line emission around these sources. Br ?, He?I and H2 emission is found at the position of all six K-band sources; we discuss whether the emission is associated with the continuum sources or whether it is ambient emission. H2 emission appears to be mostly ambient emission and no evidence of CO emission arising in the discs of YSOs has been found. We have mapped the centroid velocities of extended Br ? emission and He?I emission and found evidence of two expanding compact H?II regions. One source shows compact and strong H2 emission suggestive of a molecular outflow. The diversity of spectroscopic properties observed is interpreted in the context of a range of evolutionary stages associated with massive star formation

    Implementation and Validation of Schapery-Rand Anisotropic Viscoelasticity Model for Super-Pressure Balloons

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    The thin film used for the NASA Ultra Long Duration Balloons (ULDB) shows con-siderable time-dependent behaviour. Furthermore, experiments on scaled ULDB balloons have revealed that wrinkles are present over a wide range of pressures. A numerical model has been developed describing the nonlinear anisotropic viscoelastic material behaviour by means of a Schapery-type model and this model has been extended to model wrinkling by means of a user-defined subroutine in the finite-element package ABAQUS. After a description of the viscoelastic modelling approach, a lobe of a 48 gore ULDB flat facet balloon is modelled and compared to experimental results. Additionally two test cases of anisotropic wrinkling are presented, one involving a flat membrane and one a cylindrical balloon structure. I

    Lack of association between KIR and HLA-C type and susceptibility to idiopathic bronchiectasis

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    SummaryIntroductionIdiopathic bronchiectasis is a poorly defined disease characterised by persistent inflammation, infection and progressive lung damage. Natural killer (NK) cells provide a major defense against infection, through the interaction of their surface receptors, including the activating and inhibitory killer immunoglobulin-like receptors (KIR), and human leukocyte antigens (HLA) class I molecules. Homozygosity for HLA-C has been shown in a single study to confer increased genetic susceptibility to idiopathic bronchiectasis. We aimed to assess whether the KIR and HLA repertoire, alone or in combination, may influence the risk of developing idiopathic bronchiectasis, in an independent replication study.MethodsIn this prospective, observational, case-control association study, 79 idiopathic bronchiectasis patients diagnosed following extensive aetiological investigation were compared with 98 anonymous, healthy, age, sex and ethnically-matched controls attending blood donor sessions in the same geographical location. DNA extraction was performed according to standardised techniques. Determination of presence or absence of KIR genes was performed by a sequence specific oligonucleotide probe method. Allele frequencies for the proposed KIR, HLA-B and HLA-C risk alleles both individually and in combinations were compared.ResultsWe found no significant differences in allele frequency between the idiopathic bronchiectasis and control samples, whether considering HLA-C group homozygosity alone or in combination with the KIR type.DiscussionOur results do not show an association between HLA-C and KIR and therefore do not confirm previous positive findings. This may be explained by the lower frequency of HLA-C1 group homozygosity in the control population of the previous study (27.2%), compared to 42.3% in our study, which is consistent with the genetic profiling of control groups across the UK. The previous positive association study may therefore have been driven by an anomalous control group. Further larger prospective multicentre replication studies are needed to determine if an association exists

    Generation and phenotypic characterization of Pde1a mutant mice

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    Contains fulltext : 177029.pdf (publisher's version ) (Open Access)It has been proposed that a reduction in intracellular calcium causes an increase in intracellular cAMP and PKA activity through stimulation of calcium inhibitable adenylyl cyclase 6 and inhibition of phosphodiesterase 1 (PDE1), the main enzymes generating and degrading cAMP in the distal nephron and collecting duct, thus contributing to the development and progression of autosomal dominant polycystic kidney disease (ADPKD). In zebrafish pde1a depletion aggravates and overexpression ameliorates the cystic phenotype. To study the role of PDE1A in a mammalian system, we used a TALEN pair to Pde1a exon 7, targeting the histidine-aspartic acid dipeptide involved in ligating the active site Zn++ ion to generate two Pde1a null mouse lines. Pde1a mutants had a mild renal cystic disease and a urine concentrating defect (associated with upregulation of PDE4 activity and decreased protein kinase A dependent phosphorylation of aquaporin-2) on a wild-type genetic background and aggravated renal cystic disease on a Pkd2WS25/- background. Pde1a mutants additionally had lower aortic blood pressure and increased left ventricular (LV) ejection fraction, without a change in LV mass index, consistent with the high aortic and low cardiac expression of Pde1a in wild-type mice. These results support an important role of PDE1A in the renal pathogenesis of ADPKD and in the regulation of blood pressure

    The Hidden Strengths in Family Business: Functional Conflict

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    Conflict is likely in family businesses. Although some types of conflict are negative and should be minimized, other types are helpful and should be understood and encouraged to improve decisions. Using Jehn's (1997) framework, three types of conflict are identified and related to family business issues. A framework for conflict resolution is presented. Finally, recommendations for introducing and managing positive conflict in family businesses are offered.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
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