IA System Research Articles

Investigating Professional Analyst Strategies in Immersive Space to Think.

Existing research on sensemaking in immersive analytics systems primarily focuses on understanding how users complete analysis within these systems with quantitative and qualitative datasets. However, these user studies mainly concentrate on understanding analysis styles and methodologies from a predominantly novice user study population. While this approach provides excellent initial insights into what users may do within IA systems, it fails to address how professionals may utilize an immersive analytic system for analysis tasks. In our work, we build upon an existing immersive analytics concept - "Immersive Space to Think" to understand how professional user populations differ from novice users in immersive analytic system usage. We conducted a user study with 11 professional intelligence analysts who completed three analysis sessions each. Using our results from this study, we provide deep analysis into how professional users complete sensemaking within immersive analytic systems, compare our findings to previously published findings with a novice user population, and provide insights into how to develop better IA systems to support the professional analyst's strategies within these systems.

Mixing apples and oranges: Assessing ecological status and its confidence from multiple and diverse indicators

Ecosystem responses to increasing human pressures are complex and diverse, affecting organisms across all trophic levels. This has prompted the development of methods that integrate information across many indicators for environmental management. Legislative frameworks such as the European Water Framework Directive (WFD), specifically prescribe that integrated assessme nt (IA) of ecological status must consider indicators representing various biological and supporting quality elements. We present a general approach for an IA system based on a piece-wise linear transformation of indicator distributions to a standardized scale, allowing for integrating information from multiple and diverse indicators through a policy-dependent aggregation scheme. Uncertainties associated with monitoring data used for calculating indicators and their propagation throughout the integration scheme allow for confidence assessment at all levels of the hierarchical integration. Specific pressures leading to ecological impact can be identified through the most impaired indicators in the hierarchical and transparent aggregation scheme. The IA and its confidence are facilitated though the development of an online tool that accesses information from monitoring databases and presents the outcome at all levels of the assessment, ensuring consistency and transparency in the calculations for all potential stakeholders. We demonstrate the versality and applicability of the approach using indicators and aggregation principles from the Swedish national guidelines for assessing ecological status of rivers, lakes and coastal waters according to the WFD. Although the approach and the tool were developed specifically for the WFD ecological status assessment in Sweden, the generality of the approach implies that it can easily be adapted to the WFD assessment methods of other countries as well as other policies, where an integrated assessment is required.

Strongly lensed supernovae as a self-sufficient probe of the distance duality relation

The observation of strongly lensed Type Ia supernovae enables both the luminosity and angular diameter distance to a source to be measured simultaneously using a single observation. This feature can be used to measure the distance duality parameter $\eta(z)$ without relying on multiple datasets and cosmological assumptions to reconstruct the relation between angular and luminosity distances. In this paper, we show how this can be achieved by future observations of strongly lensed Type Ia systems. Using simulated datasets, we reconstruct the function $\eta(z)$ using both parametric and non-parametric approaches, focusing on Genetic Algorithms and Gaussian processes for the latter. In the parametric approach, we find that in the realistic scenario of $N_{\rm lens}=20$ observed systems, the parameter $\epsilon_0$ used to describe the trend of $\eta(z)$ can be constrained with the precision achieved by current SNIa and BAO surveys, while in the futuristic case ($N_{\rm lens}=1000$) these observations could be competitive with the forecast precision of upcoming LSS and SN surveys. Using the machine learning approaches of Genetic Algorithms and Gaussian processes, we find that both reconstruction methods are generally well able to correctly recover the underlying fiducial model in the mock data, even in the realistic case of $N_{\rm lens}=20$. Both approaches learn effectively from the features of the mock data points, yielding $1\sigma$ constraints that are in excellent agreement with the parameterised results.

HOLISMOKES

We present the HOLISMOKES programme on strong gravitational lensing of supernovae (SNe) as a probe of SN physics and cosmology. We investigate the effects of microlensing on early-phase SN Ia spectra using four different SN explosion models. We find that distortions of SN Ia spectra due to microlensing are typically negligible within ten rest-frame days after a SN explosion (< 1% distortion within the 1σspread and ≲10% distortion within the 2σspread). This shows the great prospects of using lensed SNe Ia to obtain intrinsic early-phase SN spectra for deciphering SN Ia progenitors. As a demonstration of the usefulness of lensed SNe Ia for cosmology, we simulate a sample of mock lensed SN Ia systems that are expected to have accurate and precise time-delay measurements in the era of theRubinObservatory Legacy Survey of Space and Time (LSST). Adopting realistic yet conservative uncertainties on their time-delay distances and lens angular diameter distances, of 6.6% and 5%, respectively, we find that a sample of 20 lensed SNe Ia would allow us to constrain the Hubble constant (H0) with 1.3% uncertainty in the flat ΛCDM cosmology. We find a similar constraint onH0in an open ΛCDM cosmology, while the constraint degrades to 3% in a flatwCDM cosmology. We anticipate lensed SNe to be an independent and powerful probe of SN physics and cosmology in the upcoming LSST era.

ТРАНСФОРМАЦИЯ МЕЖДУНАРОДНЫХ ИНФОРМАЦИОННЫХ АГЕНТСТВ

The functions of the IA system are provided by its structure. The development of the structure is associated with the emergence of new components, formats, structural links, the expansion of specialization and integration, an increase in the number of multi-format materials and the creation of interactive services. The regulator of structural ties in the system today is the presence of market relations and competition. This also determines the typology of modern information Internet agencies. Their division according to various criteria (territorial characteristics, specialization, etc.) is a necessary condition for the formation of a full-fledged system. Constant changes at different levels of this global mechanism indicate that the process is not yet complete. Network agencies continue to experiment with the format and develop the technological capabilities of their own Internet resources.

A TD‐DFT investigation of the photo‐induced excited state intramolecular proton transfer dynamics for the novel 5,5′‐(9,9‐dihexyl‐9H‐fluorene‐2,7‐diyl)bis(2‐benzo[d]thiazol‐2‐yl)phenol) system

AbstractDensity functional theory (DFT) and time‐dependent density functional theory (TDDFT) methods are adopted to explore the ground‐state and excited‐state intramolecular double hydrogen bonding interactions as well as the excited state intramolecular proton transfer (ESIPT) mechanism for 5,5′‐(9,9‐dihexyl‐9H‐fluorene‐2,7‐diyl)bis(2‐benzo[d]thiazol‐2‐yl)phenol) (abbreviated as Ia) system. The simulated electronic spectra of the Ia system (ie, absorption and fluorescence spectra) are reappeared by experimental results, which reveals the reasonability and correctness of the calculated theory adopted in this work. We firstly verify that the dual intramolecular hydrogen bonds of Ia should be enhanced in the first excited state via geometrical parameters (ie, bond lengths and bond angles) and infrared (IR) vibrational spectra. Then, insights into the photo‐excitation aspects, we confirm that the charge redistribution facilitates the ESIPT tendency. Particularly, the increased electronic densities around proton acceptors could play important roles in attracting proton H2 and H5 atoms for the Ia system. At last, via constructing potential energy surfaces (PESs), we clearly clarify the excited state intramolecular single proton transfer mechanism for the Ia system. This work not only clarifies the detailed ESIPT mechanism for the novel Ia system and makes up for the deficiencies in previous experiment but also promotes a deeper understanding about the excited state behaviors involved in multiple hydrogen bonding interactions.

Delayed Circumstellar Interaction for Type Ia SN 2015cp Revealed by an HST Ultraviolet Imaging Survey

Abstract The nature and role of the binary companion of carbon–oxygen white dwarf stars that explode as Type Ia supernovae (SNe Ia) are not yet fully understood. Past detections of circumstellar material (CSM) that contain hydrogen for a small number of SN Ia progenitor systems suggest that at least some have a nondegenerate companion. In order to constrain the prevalence, location, and quantity of CSM in SN Ia systems, we performed a near-ultraviolet (NUV) survey with the Hubble Space Telescope (HST) to look for the high-energy signature of SN Ia ejecta interacting with the CSM. Our survey revealed that SN 2015cp, an SN 1991T-like overluminous SN Ia, was experiencing late-onset interaction between its ejecta and the surrounding CSM 664 days after its light-curve peak. We present ground- and space-based follow-up observations of SN 2015cp that reveal optical emission lines of H and Ca, typical signatures of ejecta–CSM interaction. We show how SN 2015cp was likely similar to the well-studied SN Ia–CSM event PTF11kx, making it the second case in which an unambiguously classified SN Ia was observed to interact with a distant shell of CSM that contains hydrogen (R CSM ≳ 1016 cm). The remainder of our HST NUV images of SNe Ia were nondetections that we use to constrain the occurrence rate of observable late-onset CSM interaction. We apply theoretical models for the emission from ejecta–CSM interaction to our NUV nondetections and place upper limits on the mass and radial extent of CSM in SN Ia progenitor systems.

Three Hypervelocity White Dwarfs in Gaia DR2: Evidence for Dynamically Driven Double-degenerate Double-detonation Type Ia Supernovae

Abstract Double detonations in double white dwarf (WD) binaries undergoing unstable mass transfer have emerged in recent years as one of the most promising Type Ia supernova (SN Ia) progenitor scenarios. One potential outcome of this “dynamically driven double-degenerate double-detonation” (D6) scenario is that the companion WD survives the explosion and is flung away with a velocity equal to its >1000 km s−1 pre-SN orbital velocity. We perform a search for these hypervelocity runaway WDs using Gaia's second data release. In this paper, we discuss seven candidates followed up with ground-based instruments. Three sources are likely to be some of the fastest known stars in the Milky Way, with total Galactocentric velocities between 1000 and 3000 km s−1, and are consistent with having previously been companion WDs in pre-SN Ia systems. However, although the radial velocity of one of the stars is >1000 km s−1, the radial velocities of the other two stars are puzzlingly consistent with 0. The combined five-parameter astrometric solutions from Gaia and radial velocities from follow-up spectra yield tentative 6D confirmation of the D6 scenario. The past position of one of these stars places it within a faint, old SN remnant, further strengthening the interpretation of these candidates as hypervelocity runaways from binary systems that underwent SNe Ia.

On multi-frequency channel interference alignment of 3 channels and 4 users

This paper explores the multi-frequency independent channel interference alignment (MFC-IA) system of 3 channels and 4 users, and single data stream transmit, i.e. (3×3,1)4 system. We derive the analytic solution for (3×3,1)4 MFC-IA system. Based on the analytic solution, an optimization problem is proposed aim at the optimal IA solution. Then based on such a math model, we propose a simulated annealing (SA) algorithm to search optimal IA solution. The simulation results show that the simulated annealing IA algorithm has a better sum rate performance than iterative maximize signal to interference plus noise ratio (Max-SINR) algorithm. This result can be extended to single data stream multi-antenna IA system with 3 antennas and 4 users.

IMPACT ASSESSMENT RESEARCH IN BRAZIL: ACHIEVEMENTS, GAPS AND FUTURE DIRECTIONS

This paper provides an overview of current IA research in Brazil, considering its extension, lessons learned and the quality of its practice, as well as barriers to research, current gaps and future research endeavours. Despite the big effort devoted to IA research in the country, there is a small number of groups dedicated to the systematic research of IA instruments, its procedures and methods, the assessment of its effectiveness and the evidence to support good practice, the study of the organization of IA systems and their influence on decision-making. In our opinion, the lack of a well structured and distinct field of training and research is one of the major barriers to IA research. Similar to other countries, IA research is not recognised by scientific agencies/committees as a proper field of research, which means the majority of IA research grants is being evaluated/approved by committees with a small or no background in IA. There is, however, a significant contribution to be offered by research to foster IA development in Brazil. Besides the systematic assessment of IA effectiveness and the definition of procedures, methods and approaches to fill the currently well-described gaps, future research efforts should include the study of learning processes through IA practice and their influence in decision-making, the connections between IA and planning, and the benchmarks to environmental governance coming from IA practice.

Comparison of visual and automated assessment of microvessel density and their impact on outcome in primary operable invasive ductal breast cancer

Angiogenesis is essential for tumor growth and metastasis, and several studies have reported increased angiogenesis, as quantified by microvessel density, to be a powerful prognostic tool in breast cancer. Therefore, there is considerable interest in automated assessment of microvessel density with possible benefits in improved accuracy, increased precision, and handling workload. Visual and automated assessment of microvessel density (CD34(+)) and survival were examined in patients with primary operable invasive ductal breast cancer. Tissue microarrays (n = 356 patients) immunostained for microvessel density (CD34(+)) were scored visually and automatically with the Slidepath Tissue IA system (Dublin, Ireland). Visual and automated microvessel density (CD34(+)) were in agreement (interclass correlation coefficient = 0.69, P < .001). Visual but not the automated method for microvessel density (CD34(+)) was associated with locoregional treatment and metastasis. On univariate survival analysis, visual but not automated method for microvessel density (CD34(+)) was associated with recurrence-free and cancer-specific survival in patients with invasive ductal breast cancer (P < .01). Although automated assessment of microvessel density (CD34(+)) is in reasonable agreement, it poorly predicts outcome in patients with operable invasive ductal breast cancer.

Genetic determinants of PAM-dependent DNA targeting and pre-crRNA processing in Sulfolobus islandicus

Bacteria and Archaea encode clustered, regularly interspaced, short palindromic repeat (CRISPR) systems to confer adaptive immunity to invasive viruses and plasmids. Recent studies of CRISPR systems revealed that diverse CRISPR-associated (Cas) interference modules often coexist in different organisms but functions of cas genes have not been dissected in any of these systems. The crenarchaeon Sulfolobus islandicus encodes three distinct CRISPR interference modules, including a type IA system and two type IIIB systems: Cmr-α and Cmr-β. To study the genetic determinants of protospacer-adjacent motif (PAM)-dependent DNA targeting activity and mature CRISPR RNA (crRNA) production in this organism, mutants deleting individual genes of the type IA system or removing each of other Cas modules were constructed. Characterization of these mutants revealed that Cas7, Cas5, Cas6, Cas3′ and Cas3” are essential for PAM-dependent DNA targeting activity, whereas Csa5, along with all other Cas modules, is dispensable for the targeting in the crenarchaeon. Cas6 is implicated as the only enzyme for pre-crRNA processing and the crRNA maturation is independent of the DNA targeting activity. Importantly, we show that Cas7 and Cas5 are essential for stabilizing the processing intermediates and mature crRNAs, respectively, and that depleting the helicase or nuclease domain of Cas3 leads to the accumulation of processing intermediates. This demonstrates that in addition to Cas6, other Cas proteins of an archaeal type IA system also contribute to crRNA processing.

Impact Assessment and the Policy Cycle in the EU

With the Communication on Smart Regulation issued in October 2010, the European Commissiontried to foster a better management of the whole policy cycle. According to thatCommunication, amending policy proposals must be preceded by an ex-post assessmentof the current situation, allowing “closing the policy cycle”. This paper tries to answer thequestion whether the EU Impact Assessments System is fit to steer and close the policy cycle,and what is the relation between ex-ante IA and ex-post evaluation “on the ground” so far. This is done via a macro and micro analysis, based on scorecard approach and three casestudies, comparing the EU IA system performance with a theoretical benchmark derived from the EU policy document and process. The paper concludes that the EU Impact Assessmentsystem, as it is currently designed and implemented, is not yet fi t to steer and closethe policy cycle. To achieve this goal, all the analytical and empirical layers of the policycycle should be fully dealt with since the ex-ante phase.

Comparison of visual and automated assessment of HER2 status and their impact on outcome in primary operable invasive ductal breast cancer

To compare visual and computerized image analysis of HER2 immunohistochemistry (IHC) with fluorescence in-situ hybridization (FISH) for HER2 status, and to examine the relationships with outcome in patients with primary operable invasive ductal breast cancer. Tissue microarrays for 431 breast cancer patients were used to compare different approaches to the assessment of HER2 status. The cores were scored visually and with the Slidepath Tissue IA system, using the NICE-approved scoring system for the HercepTest, as well as by FISH. The agreement between visual and image analysis of HER2 IHC was excellent [interclass correlation coefficient (ICCC) = 0.95, rs = 0.90, r = 0.91, k = 0.81, and P < 0.001]. The agreement of HER2 FISH with visual and image analysis of HER2 IHC was also excellent (ICCC = 0.95 and ICCC = 0.92, respectively). Univariate survival analysis showed equivalent associations of visual and image analysis of HER2 and HER2 FISH with both recurrence-free survival (all P < 0.01) and cancer-specific survival (all P < 0.05) in patients with invasive ductal breast cancer. Computerized image analysis of HER2 IHC gives results comparable to those obtained with visual assessment, with possible advantages in diagnostic pathology.

The Development of RIA in the European Union: An Overview

The European Commission has successfully managed to adopt and implement ex ante impact assessment procedures since 2003, and available data show that the IA documented are of increasingly good quality. Even though margins for improving the European Commission IA system persist, other EU institutions and almost all EU member states significantly lag behind in terms of IA implementation. The experience of past research projects, including the European Network for Better Regulation and the recent OECD EU15 project confirmed that at national level IA features a high adoption-implementation gap. This paper draws on EU and international experience to draw some recommendations, which include the need for more sophisticated legal and economic analysis in RIA, to make it a more credible instrument for ex ante policy appraisal; and the need for gradually introduced, carefully designed RIA system which take advantage of the enormous success obtained by other, simpler models, such as the Standard Cost Model for the measurement and reduction of administrative burdens.

The Chilean pension reform: A model to follow?

One of the major economic reforms in the Chilean economy was the 1981 pension reform. In that year, Chile transformed its Pay-as-you-go social (PAYG) security system to an individual account social security system (IA). This paper discusses the impacts of the social security reform. To do so, we construct a countra-factual scenario of the Chilean economy under the PAYG system using simulations methods and we compare it with the effective data occurred under the IA system. We discuss the fiscal impacts, plus pension coverage on the elderly and the PAYG system's macroeconomics impacts by comparing them with the actual evolution of the Chilean economy under the IA system. Our simulations show significant fiscal deficits in the PAYG plus relatively lower pension coverage and modest benefits compare to the IA system. Finally, we show that the pension reform might have had significant macroeconomic impacts.

Multicolor Light Curves of Type Ia Supernovae on the Color‐Magnitude Diagram: A Novel Step toward More Precise Distance and Extinction Estimates

We show empirically that fits to the color-magnitude relation of Type Ia supernovae (SNe Ia) after optical maximum can provide accurate relative extragalactic distances. We report the discovery of an empirical color relation for SN Ia light curves: during much of the first month past maximum, the magnitudes of SNe Ia defined at a given value of color index have a very small magnitude dispersion; moreover, during this period the relation between B magnitude and B-V color (or B-R or B-I color) is strikingly linear, to the accuracy of existing well-measured data. These linear relations can provide robust distance estimates, in particular, by using the magnitudes when the SN reaches a given color. After correction for light-curve stretch factor or decline rate, the dispersion of the magnitudes taken at the intercept of the linear color-magnitude relation is found to be around 0.08 mag for the subsample of SNe with (Bmax-Vmax) ≤ 0.05 mag and around 0.11 mag for the subsample with (Bmax-Vmax) ≤ 0.2 mag. This small dispersion is consistent with being mostly due to observational errors. The method presented here and the conventional light-curve fitting methods can be combined to further improve statistical dispersions of distance estimates. It can be combined with the magnitude at maximum to deduce dust extinction. The slopes of the color-magnitude relation may also be used to identify intrinsically different SN Ia systems. The method provides a tool that is fundamental to using SNe Ia to estimate cosmological parameters such as the Hubble constant and the mass and dark energy content of the universe.

Monosynaptic Ia pathways at the cat shoulder.

1. The study aimed to describe in cat forelimb and shoulder motoneurones the convergence and projection patterns from large muscle spindle afferents (Ia). In 11 chloralose-anaesthetized cats maximum Ia EPSPs evoked by electrical stimulation of ipsilateral forelimb nerves were obtained in 309 intracellularly recorded alpha-motoneurones. 2. Groups of motor nuclei displayed similar Ia patterns. As in the distal forelimb they were often interconnected by bidirectional pathways, which were used to combine Ia synergistic groups. Three such groups are described at the shoulder. 3. The first group was composed of the main flexors of the scapulo-humeral joint. Regular disto-proximal Ia excitation from elbow extensors (and median afferents) indicates a coupling of flexion in the scapulo-humeral joint to the angular position of the elbow. 4. The second group comprised the outward rotators of the humerus with differentiated Ia convergence onto the different group members. The patterns of Ia excitation received and sent by the group members demonstrate that the outward rotators are incorporated in versatile synergisms and may occupy a central position in steering forelimb movements. 5. The third group was formed by the spinatus muscle and the subscapularis. This arrangement is suggested by the common convergence onto them from the elbow extensors and flexors. The pattern may serve to guide and keep the humeral head in the joint capsule. 6. The Ia synergistic groups receive Ia convergence from muscles acting at distant joints and also project to distant muscles. This is discussed as part of an extended pattern of Ia connections along the forelimb. In this way the shoulder muscles would be incorporated in flexor and extensor oriented synergisms which are needed to co-ordinate the muscular activation along the multijoint forelimb during locomotion. When the shoulder Ia pathways are compared with those in the distal forelimb, organization of the Ia system apparently follows a few basic principles which have adapted to the mechanical situation at the particular joints and their mechanical interaction.

ClpX and ClpP are essential for the efficient acquisition of genes specifying type IA and IB restriction systems.

Efficient acquisition of genes that encode a restriction and modification (R-M) system with specificities different from any already present in the recipient bacterium requires the sequential production of the new modification enzyme followed by the restriction activity in order that the chromosome of the recipient bacterium is protected against attack by the restriction endonuclease. We show that ClpX and ClpP, the components of ClpXP protease, are necessary for the efficient transmission of the genes encoding EcoKI and EcoAI, representatives of two families of type I R-M systems, thus implicating ClpXP in the modulation of restriction activity. Loss of ClpX imposed a bigger barrier than loss of ClpP, consistent with a dual role for ClpX, possibly as a chaperone and as a component of the ClpXP protease. Transmission of genes specifying EcoKI was more dependent on ClpX and ClpP than transmission of the genes for EcoAI. Sensitivity to absence of the protease was also influenced by the mode of gene transfer; conjugative transfer and transformation were more dependent on ClpXP than transduction. In the absence of either ClpX or ClpP transfer of the EcoKI genes by P1-mediated transduction was impaired, transfer of the EcoAI genes was not.

Regulation of the Activity of the type IC EcoR124I Restriction Enzyme

Restriction-modification (R-M) systems must regulate the expression of their genes so that the chromosomal genome is modified at all times by the methyltransferase to protect the host cell from the potential lethal action of the cognate restriction endonuclease. Since type I R-M systems can be transferred to non-modified Escherichia colicells by conjugation or transformation without killing the recipient, they must have some means to regulate their restriction activity upon entering a new host cell to avoid restriction of unprotected host DNA and cell death. This is especially true for EcoR124I, a type IC family member, which is coded for by a conjugative plasmid. Control of EcoR124I restriction activity is most likely at the post-translational level as the transfer of the EcoR124I system into a recipient cell that already expressed the HsdR subunit of this system was not a lethal event. Additionally, the kinetics of restriction activity upon transfer of the genes coding for the EcoR124I RM system to a recipient cell are the same, irrespective of the modification state of the recipient cell or the presence or absence of the EcoR124I HsdR subunit in the new host cells. The mechanism controlling the restriction activity of a type IC R-M system upon transfer to a new host cell is different from that controlling the chromosomally coded type IA and IB R-M systems. The previously discovered hsdC mutant, which affects the establishment of the type IA system EcoKI, was shown to affect the establishment of the type IB system EcoAI, but to have no influence on EcoR124I.