Catastrophic Errors Research Articles

Near miss event: Sentinel to identifying catastrophic errors in transfusion chain

Near miss event: Sentinel to identifying catastrophic errors in transfusion chain

Two wrongs do not make a right: the assumption that an inhibitor acts as an inverse activator

Models of biochemical networks are often large intractable sets of differential equations. To make sense of the complexity, relationships between genes/proteins are presented as connected graphs, the edges of which are drawn to indicate activation or inhibition relationships. These diagrams are useful for drawing qualitative conclusions in many cases by the identifying recurring of topological motifs, for example positive and negative feedback loops. These topological features are usually classified under the presumption that activation and inhibition are inverse relationships. For example, inhibition of an inhibitor is often classified the same as activation of an activator within a motif classification, effectively treating them as equivalent. Whilst in many contexts this may not lead to catastrophic errors, drawing conclusions about the behavior of motifs, pathways or networks from these broad classes of topological feature without adequate mathematical descriptions can lead to obverse outcomes. We investigate the extent to which a biochemical pathway/network will behave quantitatively dissimilar to pathway/ networks with similar typologies formed by swapping inhibitors as the inverse of activators. The purpose of the study is to determine under what circumstances rudimentary qualitative assessment of network structure can provide reliable conclusions as to the quantitative behaviour of the network. Whilst there are others, We focus on two main mathematical qualities which may cause a divergence in the behaviour of two pathways/networks which would otherwise be classified as similar; (i) a modelling feature we label ‘bias’ and (ii) the precise positioning of activators and inhibitors within simple pathways/motifs.

Informating and Automating in Systems Design: Extending the Zuboffian View of Technology Ready-to-Use vs. Technology Unintuitive-to-Use

ABSTRACT Previous literature has treated software functionalities as a binary choice between informating and automating, based on Zuboff’s definitions. We suggest that the space between the role of a user engaging with a system (informate) and what the system can accomplish for the user (automate) has increasingly become blurred, moving toward a more nuanced continuum. We present a user-system interaction framework that analyzes this continuum with a focus on the user’s perspective. Using cases from archival data, this paper provides an analysis of what goes well and badly in the locus of control handoff between users and systems, highlighting the implications of software that is created in one region but used globally. The paper contributes to the literature by extending Zuboff’s informate vs. automate discussion and identifying design decisions that could help to avoid potentially catastrophic design errors. Using the interaction framework, we argue that it would be beneficial for system designers to move toward the informate end of the continuum, when designing systems for users with a high level of domain knowledge and expertise, and when there are significant differences between the environment in which the system is designed and the one in which the system is used.

Automated translation accurately translates recorded pediatric neurosurgery clinic conversations between Spanish and English.

The purpose of this study is to analyze an automated voice to text translation device by reporting the translation accuracy for recorded pediatric neurosurgery clinic conversations, classifying errors in translation according to their impact on overall understanding, and comparing the incidence of these errors in English to Spanish vs. Spanish to English conversations. English and Spanish speaking patients at a single academic health system's outpatient pediatric neurosurgery clinic had their conversations recorded. These recordings were played back to a Google Pixel handheld smartphone with Live Translate voice to text translation software. A certified medical interpreter evaluated recordings for incidence of minor errors, errors impacting understanding, and catastrophic errors affecting patient-provider relationship or care. Two proportion t-testing was used to compare these outcomes. 50 patient visits were recorded: 40 English recordings translated to Spanish and 10 Spanish recordings translated to English. The mean transcript length was 4244 ± 992 words. The overall accuracy was 98.2% ± 0.5%. On average, 46 words were missed in translation (1.09% error rate), 31 understanding-altering translation errors (0.73% error rate), and 0 catastrophic errors were made. There was no significant difference in English to Spanish or vice versa. Voice to text translation devices using automatic speech recognition accurately translate recorded clinic conversations between Spanish and English with high accuracy and low incidence of errors impacting medical care or understanding. Further study should investigate additional languages, assess patient preferences and potential concerns with respect to device use, and compare these devices directly to medical interpreters in live clinic settings.

Quaia, the Gaia-unWISE Quasar Catalog: An All-sky Spectroscopic Quasar Sample

We present a new, all-sky quasar catalog, Quaia, that samples the largest comoving volume of any existing spectroscopic quasar sample. The catalog draws on the 6,649,162 quasar candidates identified by the Gaia mission that have redshift estimates from the space observatory’s low-resolution blue photometer/red photometer spectra. This initial sample is highly homogeneous and complete, but has low purity, and 18% of even the bright (G < 20.0) confirmed quasars have discrepant redshift estimates (∣Δz/(1 + z)∣ > 0.2) compared to those from the Sloan Digital Sky Survey (SDSS). In this work, we combine the Gaia candidates with unWISE infrared data (based on the Wide-field Infrared Survey Explorer survey) to construct a catalog useful for cosmological and astrophysical quasar studies. We apply cuts based on proper motions and colors, reducing the number of contaminants by approximately four times. We improve the redshifts by training a k-Nearest Neighbor model on SDSS redshifts, and achieve estimates on the G < 20.0 sample with only 6% (10%) catastrophic errors with ∣Δz/(1 + z)∣ > 0.2 (0.1), a reduction of approximately three times (approximately two times) compared to the Gaia redshifts. The final catalog has 1,295,502 quasars with G < 20.5, and 755,850 candidates in an even cleaner G < 20.0 sample, with accompanying rigorous selection function models. We compare Quaia to existing quasar catalogs, showing that its large effective volume makes it a highly competitive sample for cosmological large-scale structure analyses. The catalog is publicly available at 10.5281/zenodo.10403370.

Understanding Automation Failure

The implementation of automation in many domains has led to well-documented accidents and incidents, resulting from reduced situation awareness that occurs when operators are out-of-loop (OOTL), automation confusion, and automation interaction difficulties. Wickens coined the term lumberjack effect to summarize the finding that while automation works well most of the time in typical or normal situations, the performance problems that occur in novel or unexpected situations also increase the likelihood of catastrophic errors. Skraaning and Jamieson have criticized the lumberjack effect due to a study in which they failed to find it. I show that this claim is unsupported due to a number of methodological limitations in their study and conceptual errors. They also provide a model of automation failure that fails to clearly delineate the many barriers to accidents that are available, instead emphasizing the ways in which automation can fail technically and different types of human error. An alternate automation failure model is presented that provides a broader socio-technical perspective emphasizing the design features, processes, capabilities, organizational policies, and training that support people in improving system safety when automation fails.

Analysis of the impact of broad absorption lines on quasar redshift measurements with synthetic observations

ABSTRACT Accurate quasar classifications and redshift measurements are increasingly important to precision cosmology experiments. Broad absorption line (BAL) features are present in 15–20 per cent of all quasars, and these features can introduce systematic redshift errors, and in extreme cases produce misclassifications. We quantitatively investigate the impact of BAL features on quasar classifications and redshift measurements with synthetic spectra that were designed to match observations by the Dark Energy Spectroscopic Instrument (DESI) survey. Over the course of 5 yr, DESI aims to measure spectra for 40 million galaxies and quasars, including nearly three million quasars. Our synthetic quasar spectra match the signal-to-noise ratio and redshift distributions of the first year of DESI observations, and include the same synthetic quasar spectra both with and without BAL features. We demonstrate that masking the locations of the BAL features decreases the redshift errors by about 1 per cent and reduces the number of catastrophic redshift errors by about 80 per cent. We conclude that identifying and masking BAL troughs should be a standard part of the redshift determination step for DESI and other large-scale spectroscopic surveys of quasars.

Constituting absence as reliability: The case of COVID‐19 response networks

AbstractHigh reliability organizations (HROs) are rare organizations that manage established technologies to avoid catastrophic errors. The concept of reliability, however, has become attractive to other organization types. This expansion creates scholarly questions about what reliability is outside of HROs. The COVID‐19 pandemic challenged new organizations to create reliability by also creating alternative meanings and practices of reliability that could adequately address an unknown, evolving health threat. This study draws on semistructured interviews and virtual ethnography during the first year of the COVID‐19 pandemic to examine how organizations communicatively defined reliability. The study finds that organizations engage in datafication of hazards to demonstrate they are performing reliably and proposes the practice of “evidencing reliability” as an important step in constituting reliability. However, datafication of hazards can also lead to skewed understandings of organizational performance and potential success biases.

Confirmation and refutation of very luminous galaxies in the early Universe.

During the first 500 million years of cosmic history, the first stars and galaxies formed, seeding the Universe with heavy elements and eventually reionizing the intergalactic medium1-3. Observations withtheJames Webb Space Telescope (JWST) have uncovered a surprisingly high abundance of candidates for early star-forming galaxies, with distances (redshifts, z), estimated from multiband photometry, as large as z ≈ 16, far beyond pre-JWST limits4-9. Althoughsuch photometric redshifts are generally robust, they can suffer from degeneracies and occasionally catastrophic errors. Spectroscopic measurements are required to validate these sources and to reliably quantify physical properties that can constrain galaxy formation models and cosmology10. Here we present JWST spectroscopy that confirms redshifts for two very luminous galaxies with z > 11, and also demonstrates that another candidate with suggested z ≈ 16 instead has z = 4.9, with an unusual combination of nebular line emission and dust reddening that mimics the colours expected for much more distant objects. These results reinforce evidence for the early, rapid formation of remarkably luminous galaxies while also highlighting the necessity of spectroscopic verification. The large abundance of bright, early galaxies may indicate shortcomings in current galaxy formation models or deviations from physical properties (such as the stellar initial mass function) that are generally believed to hold at later times.

Redundant representations are required to disambiguate simultaneously presented complex stimuli.

A pedestrian crossing a street during rush hour often looks and listens for potential danger. When they hear several different horns, they localize the cars that are honking and decide whether or not they need to modify their motor plan. How does the pedestrian use this auditory information to pick out the corresponding cars in visual space? The integration of distributed representations like these is called the assignment problem, and it must be solved to integrate distinct representations across but also within sensory modalities. Here, we identify and analyze a solution to the assignment problem: the representation of one or more common stimulus features in pairs of relevant brain regions-for example, estimates of the spatial position of cars are represented in both the visual and auditory systems. We characterize how the reliability of this solution depends on different features of the stimulus set (e.g., the size of the set and the complexity of the stimuli) and the details of the split representations (e.g., the precision of each stimulus representation and the amount of overlapping information). Next, we implement this solution in a biologically plausible receptive field code and show how constraints on the number of neurons and spikes used by the code force the brain to navigate a tradeoff between local and catastrophic errors. We show that, when many spikes and neurons are available, representing stimuli from a single sensory modality can be done more reliably across multiple brain regions, despite the risk of assignment errors. Finally, we show that a feedforward neural network can learn the optimal solution to the assignment problem, even when it receives inputs in two distinct representational formats. We also discuss relevant results on assignment errors from the human working memory literature and show that several key predictions of our theory already have support.

Are single-peaked tuning curves tuned for speed rather than accuracy?

According to the efficient coding hypothesis, sensory neurons are adapted to provide maximal information about the environment, given some biophysical constraints. In early visual areas, stimulus-induced modulations of neural activity (or tunings) are predominantly single-peaked. However, periodic tuning, as exhibited by grid cells, has been linked to a significant increase in decoding performance. Does this imply that the tuning curves in early visual areas are sub-optimal? We argue that the time scale at which neurons encode information is imperative to understanding the advantages of single-peaked and periodic tuning curves. Here, we show that the possibility of catastrophic (large) errors creates a trade-off between decoding time and decoding ability. We investigate how decoding time and stimulus dimensionality affect the optimal shape of tuning curves for removing catastrophic errors. In particular, we focus on the spatial periods of the tuning curves for a class of circular tuning curves. We show an overall trend for minimal decoding time to increase with increasing Fisher information, implying a trade-off between accuracy and speed. This trade-off is reinforced whenever the stimulus dimensionality is high, or there is ongoing activity. Thus, given constraints on processing speed, we present normative arguments for the existence of the single-peaked tuning organization observed in early visual areas.

Radiotherapy delivery error detection with electronic portal imaging device (EPID)-based in vivo dosimetry.

Radiotherapy delivery error detection with electronic portal imaging device (EPID)-based in vivo dosimetry.

Forecasts for cosmological measurements based on the angular power spectra of AGN and clusters of galaxies in the SRG/eROSITA all-sky survey

Context. The eROSITA X-ray telescope aboard the Spectrum-Roentgen-Gamma (SRG) orbital observatory, in the course of its all-sky survey, is expected to detect about three million active galactic nuclei (AGNs) and approximately one hundred thousand clusters and groups of galaxies. Such a sample, clean and uniform, complemented with redshift information, will open a new window into the studies of the large-scale structure (LSS) of the Universe and the determination of its cosmological parameters. Aims. The purpose of this work is to assess the prospects of cosmological measurements with the eROSITA sample of AGNs and clusters of galaxies. We assumed the availability of photometric redshift measurements for eROSITA sources and explored the impact of their quality on our forecasts. Methods. As the LSS probe, we use the redshift-resolved angular power spectrum of the density fluctuations of objects. We employed a Fisher-matrix formalism and assumed flat ΛCDM cosmology to forecast the constraining power of eROSITA samples of AGNs and clusters of galaxies. We computed the LSS-relevant characteristics of AGNs and clusters in the framework of the halo model and their X-ray luminosity functions. As the baseline scenario, we considered the full four-year all-sky survey and investigated the impact of reducing the survey length to two years. Results. We find that the accuracy of photometric redshift estimates has a more profound effect on cosmological measurements than the fraction of catastrophic errors. Under realistic assumptions about the photometric redshift quality, the marginalised errors on the cosmological parameters achieve 1 − 10% accuracy depending on the cosmological priors used from other experiments. The statistical significance of Baryon acoustic oscillation detection in angular power spectra of AGNs and clusters of galaxies considered individually achieves 5 − 6σ. Our results demonstrate that the eROSITA sample of AGNs and clusters of galaxies used in combination with currently available photometric redshift estimates will provide cosmological constraints on a par with dedicated optical LSS surveys.

A Catalog of Candidate Double and Lensed Quasars from Gaia and WISE Data

Making use of strong correlations between closely separated multiple or double sources and photometric and astrometric metadata in Gaia Early Data Release 3 (EDR3), we generate a catalog of candidate double- and multiply imaged lensed quasars and active galactic nuclei (AGNs), comprising 3140 systems. It includes two partially overlapping parts: a sample of distant (redshifts mostly greater than 1) sources with perturbed data; and systems that have been resolved into separate components by Gaia at separations less than 2″. For the first part, which is roughly one-third of the published catalog, we synthesized 0.617 million redshifts using multiple machine-learning prediction and classification methods, using independent photometric and astrometric data from Gaia EDR3 and the Wide-field Infrared Survey Explorer, with accurate spectroscopic redshifts from the Sloan Digital Sky Survey (SDSS) as a training set. Using these synthetic redshifts, we estimate a 4.9% rate of interlopers with spectroscopic redshifts below 1 in this part of the catalog. Unresolved candidate double and dual AGNs and quasars are selected as sources with a marginally high BP/RP excess factor (phot_bp_rp_excess_factor), which is sensitive to source extent, limiting our search to high-redshift quasars. For the second part of the catalog, additional filters on measured parallax and near-neighbor statistics are applied to diminish the propagation of the remaining stellar contaminants. The estimated rate of the positives (double or multiple sources) is 98%, and the estimated rate of dual (physically related) quasars is greater than 54%. A few dozen serendipitously found objects of interest are discussed in more detail, including known and new lensed images, planetary nebulae, young IR stars of peculiar morphology, and quasars with catastrophic redshift errors in SDSS.

Distributed Quantum Error Correction for Chip-Level Catastrophic Errors.

Quantum error correction holds the key to scaling up quantum computers. Cosmic ray events severely impact the operation of a quantum computer by causing chip-level catastrophic errors, essentially erasing the information encoded in a chip. Here, we present a distributed error correction scheme to combat the devastating effect of such events by introducing an additional layer of quantum erasure error correcting code across separate chips. We show that our scheme is fault tolerant against chip-level catastrophic errors and discuss its experimental implementation using superconducting qubits with microwave links. Our analysis shows that in state-of-the-art experiments, it is possible to suppress the rate of these errors from 1per 10s to less than 1per month.

DELIGHT: Deep Learning Identification of Galaxy Hosts of Transients using Multiresolution Images

We present DELIGHT, or Deep Learning Identification of Galaxy Hosts of Transients, a new algorithm designed to automatically and in real time identify the host galaxies of extragalactic transients. The proposed algorithm receives as input compact, multiresolution images centered at the position of a transient candidate and outputs two-dimensional offset vectors that connect the transient with the center of its predicted host. The multiresolution input consists of a set of images with the same number of pixels, but with progressively larger pixel sizes and fields of view. A sample of 16,791 galaxies visually identified by the Automatic Learning for the Rapid Classification of Events broker team was used to train a convolutional neural network regression model. We show that this method is able to correctly identify both relatively large (10″ < r < 60″) and small (r ≤ 10″) apparent size host galaxies using much less information (32 kB) than with a large, single-resolution image (920 kB). The proposed method has fewer catastrophic errors in recovering the position and is more complete and has less contamination (<0.86%) recovering the crossmatched redshift than other state-of-the-art methods. The more efficient representation provided by multiresolution input images could allow for the identification of transient host galaxies in real time, if adopted in alert streams from new generation of large -etendue telescopes such as the Vera C. Rubin Observatory.

ARPIST: Provably accurate and stable numerical integration over spherical triangles

Numerical integration on spherical triangles, including the computation of their areas, is a core computation in geomathematics. The commonly used techniques sometimes suffer from instabilities and significant loss of accuracy. We describe a new algorithm, called ARPIST, for accurate and stable integration of functions on spherical triangles. ARPIST is based on an easy-to-implement transformation to the spherical triangle from its corresponding linear triangle via radial projection to achieve high accuracy and efficiency. More importantly, ARPIST overcomes potential instabilities in computing the Jacobian of the transformation, even for poorly shaped triangles that may occur at poles in regular longitude-latitude meshes, by avoiding potential catastrophic rounding errors. We compare our proposed technique with L’Huilier’s Theorem for computing the area of spherical triangles, and also compare it with the recently developed LSQST method (Beckmann et al., 2014) and a radial-basis-function-based technique (Reeger and Fornberg, 2016) for integration of smooth functions on spherical triangulations. Our results show that ARPIST enables better or comparable accuracy over previous methods while being easier to implement, significantly faster, and more tolerant of poor element shapes.

A built-in self-test module for 16-bit parallel photon counting circuit using 180 nm CMOS process

This study investigated the use of a built-in-self-test (BIST) module detecting catastrophic errors in photon-counter accumulator for liquid contamination level measurement. Efficient algorithms are exceptionally demanded for a high-count rate and low voltage system photon counting circuit on-chip. The photon counter sensors are also required high sensitivity digital counter that encodes the arrival of photon in precise timing to prevent any count erroring the absence of light. The proposed BIST is integrated on the data acquisition system, where the accumulator is located. The design circuit, functionality and topology tests of BIST and circuit under test are realized with 180 nm Silterra CMOS Process. The same Verilog codes are verified using field programmable gate array (FPGA) to predict the hardware functionality prior fabrication. The measurement was able to detect at least 90 % fault coverage within 16-bit data acquisition system at minimum operating frequency of 166.7 MHz.

Dynamic navigation: how far it would go in endodontics?

No doubt that the great revolution of digital dentistry has opened the door wide for treatment options that would not otherwise exist and the field of endodontics sets no exception for that. The concept of dynamic navigation (DN) has been recently introduced to be applied not only in difficult cases that otherwise lead to catastrophic errors, but would go far till everyday practice. The present study is designed to systematically review the application of DN in endodontics. Furthermore, meta-analysis was conducted to assess the accuracy and feasibility of the use of DN as compared to conventional endodontics. A comprehensive review was performed by two independent reviewers who conducted a literature search using a combination of keywords in four different electronic databases. Fifteen eligible articles were included and reviewed in the systematic review; of which 10 were included in the meta-analysis to assess different aspects such as accuracy, efficiency as reflected by time consumed, dentine loss, and effect of operator experience. DN showed statistically significant lower linear and angular deviation as well as dentine loss. Nevertheless, studies that included more than one operator of different levels of experience showed a statistically non-significant difference. Dynamic navigation is a valuable, accurate, and effective modality in endodontics that would ensure accuracy even for the less experienced operator and allow for a new era of digitalized endodontic practice.

Analysis of Climate Variability in a Time Series of Precipitation and Temperature Data: A Case Study in Cartagena de Indias, Colombia

Anthropogenic climate change is a global trend, hitherto incontrovertible, causing immense social and economic damage. Although the this is evident at the global level, at the local level, there is still debate about the most appropriate analyses to support this fact. This debate is particularly relevant in developing countries, such as Colombia, where there is a significant lack of data at the local level that require analysis and interpretation. Consequently, studies are often superficially conducted to support climate change theory at the local level. However, such studies are then used to design hydraulic infrastructure, with potential catastrophic errors for human and environmental health. In this study, we sought evidence of climate change through an analysis of a series of data on temperature (maximum, mean and minimum), as well as total annual and maximum rainfall in 24 h registered at the Rafael Nuñez Airport station in the city of Cartagena, Colombia, from 1941 to 2015. The hypotheses of homogeneity, trend, stationarity and non-stationarity were analyzed. Problems of non-homogeneity and the presence of periodicity in the analyzed series were found, showing a trend and apparent non-stationarity in the original series. This could be associated with the effects of climate change. In this case, no correlation was found between temperatures and rainfall. Spectral analysis was performed for all series, and residual series were generated by extracting the harmonics of greatest significance. It was found that the series data generated from the third harmonic are generally stationary and without trend. Therefore, the trend and non-stationarity of the original series are due to problems of non-homogeneity and periodicity in the series. In the results of the stationarity test conducted according to the Phillips–Perron criterion, all series were non-stationary. For the two additional criteria of stationarity tests, 40% were shown to be stationary, and 60% were non-stationary. Specifically, non-homogeneity problems and apparent trends associated with climate change could have negative implications for the design of drainage systems.