Related Artifacts Research Articles

Comparison of high-pitch prospective electrocardiogram-gated pulmonary CT angiography with standard CT pulmonary angiography on dual-source CT for detection of subsegmental pulmonary embolism in patients suspected of acute pulmonary embolism.

PurposeObjective of this study was to compare high-pitch prospective electrocardiogram (ECG)-gated computed tomography (CT) pulmonary angiography (HP-PECG-gated CTPA) with standard-pitch non-ECG-gated CT pulmonary angiography (SP-NECG-gated CTPA) on 128-slice dual-source CT (DSCT) for the detection of subsegmental pulmonary embolism (SSPE) in patients suspected of acute pulmonary embolism (APE) with radiation and contrastoptimized protocols. Cardiac-related motion artefacts, lung image quality, and quantitative parameter (pulmonary arterial enhancement, radiation exposure, and contrast) volumes were also compared.Material and methodsThis prospective study enrolled 87 patients clinically suspected of APE and randomly distributed to either group by software. Two radiologists blinded to each other interpreted the images for assessment of SSPE, image quality, and quantitative parameters.ResultsSSPE was diagnosed in 15/44 (34.09%) patients in HP-PECG-gated CTPA, in comparison to 8/43 (18.60%) patients in SP-NECG-gated CTPA. Cardiac motion-related artefacts (blurring of bronchovascular structures and double-line artefacts) were statistically significantly less, with p-value < 0.05. Lung image quality was also better, with p-value < 0.001. Effective radiation dose and contrast volume in HP-PECG-gated CTPA were (2.54 ± 0.80 mSv, 45.05 ± 6 ml) versus SP-NECG-gated CTPA (3.17 ± 1.20 mSv, 74.19 ± 7.63 ml) with p-values of 0.007 and 0.001, respectively.ConclusionsRadiation and contrast volume-optimized HP-PECG-gated CTPA provides reduced cardiac motion related artefacts of pulmonary arteries, which allows enhanced detection of SSPE. It also provides better image quality of lung and parenchyma with lower radiation exposure and less contrast volume

Time-resolved, Cardiac-gated Computed Tomography After Endovascular Ascending Aortic and Arch Repair

PurposeBetter time-resolved imaging of stent grafts in the ascending aorta and arch accounting for cardiac motion is necessary to understand device-related complications and endoleaks. This report describes dynamic time-resolved computed tomographic angiography (d-CTA) and its combination with electrocardiography gating (d-gated CTA) to image stent grafts in the ascending aorta and to characterize endoleaks more clearly. Descriptiond-CTA involves multiple scans acquired at different time points along the contrast enhancement curve. d-Gated CTA involves concomitant electrocardiography gating in a predefined cardiac phase minimizing motion-induced artifacts. EvaluationThis report illustrates the utility of d-CTA and d-gated CTA in 2 clinical cases. d-CTA demonstrated a type 1A endoleak in a patient with an aortic arch aneurysm treated with total arch debranching and a thoracic stent graft. d-gated CTA demonstrated a type 1A endoleak in a patient with an ascending aortic pseudoaneurysm treated with aortic cuff placement. ConclusionsDynamic, cardiac-gated CTA enables time-resolved angiographic imaging of the ascending aorta and arch without any cardiac motion–related artifacts. Such advanced imaging techniques help with better characterization of endoleaks after stent graft deployment in the ascending aorta and arch.

Quantitative analysis of metal artifact reduction in total hip arthroplasty using virtual monochromatic imaging and orthopedic metal artifact reduction, a phantom study

ObjectiveTo quantify metal artifact reduction using 130 keV virtual monochromatic imaging (VMI) with and without orthopedic metal artifact reduction (O-MAR) in total hip arthroplasty.MethodsConventional polychromatic images and 130 keV VMI of a phantom with pellets representing bone with unilateral or bilateral prostheses were reconstructed with and without O-MAR on a dual-layer CT. Pellets were categorized as unaffected, mildly affected and severely affected.ResultsWhen 130 keV VMI with O-MAR was compared to conventional imaging with O-MAR, a relative metal artifact reduction in CT values, contrast-to-noise (CNR), signal-to-noise (SNR) and noise in mildly affected pellets (67%, 74%, 48%, 68%, respectively; p < 0.05) was observed but no significant relative metal artifact reduction in severely affected pellets. Comparison between 130 keV VMI without O-MAR and conventional imaging with O-MAR showed relative metal artifact reduction in CT values, CNR, SNR and noise in mildly affected pellets (92%, 72%, 38%, 51%, respectively; p < 0.05) but negative relative metal artifact reduction in CT values and noise in severely affected pellets (− 331% and -223%, respectively; p < 0.05), indicating aggravation of metal artifacts.ConclusionOverall, VMI of 130 keV with O-MAR provided the strongest metal artifact reduction.

Identifying mixtures of metals by multi‐isotope analysis: Disentangling the relationships of the Early Bronze Age swords of the Apa–Hajdúsámson type and associated objects

AbstractThis pilot study addresses the analytical characterisation of 26 well‐known bronze objects of the Early and Middle Bronze Age of Central and Northern Europe. Besides swords and axes of the hoards from Apa, Téglás and Hajdúsámson, the investigation includes the famous Sky Disc and its accompanying finds from the Nebra hoard and several full‐hilted swords from Period I in Denmark. In contrast to former publications, the isotopic systematics of lead, tin and copper are the focus of the present investigation. With a combined approach, we try to relate the typologically closely linked or otherwise related artefacts with chemical and isotopic proxies by identifying mixing scenarios. The results demonstrate that artefacts from different locations are most likely not directly linked, but mixing lines across isotope systems suggest a production of the items from common sources by mixing of bronze batches (e.g., bronze ingots), which were probably disseminated between 1600 and 1500 bce. This helps to correlate objects of different locations with each other and to draw conclusions upon typological and cultural connections. Isotopic and chemical correlations of objects within the individual hoards, on the other hand, allow reconstructions of metallurgical practices in single workshops, which, for example, implies recycling of metal scrap.

Romantic relationship dissolution on social networking sites: Self-Presentation and public accounts of breakups on Facebook

Social media users post an endless stream of life updates, commentary, and other content. This online self-presentation constitutes a narrative that can be examined as a shared account. In this study, we tested the applicability of Duck’s model of relational dissolution (Duck, 1982; Rollie &amp; Duck, 2006) to participants’ personal and public accounts of their romantic breakups on social networking sites (also referred to as social network sites). We adopted mixed methods (content analysis, survey, and interview) to examine emerging adults’ ( N = 97) account-making during romantic relationship dissolution and the role of social media, specifically Facebook, in the process. Over 3500 posts and comments from before and after users’ breakups were quantitatively and qualitatively content analyzed. Synthesizing these three data sources revealed patterns regarding users’ selective self-presentation in masspersonal channels. Their dissolution accounts were shaped by perceptions of Facebook’s social affordances, such as the visibility and persistence of posts, comments, and relational artifacts; social feedback (e.g., comments and “likes” from the online social network, usually for social support); conversational control (e.g., blocking and defriending); and network association, which created a diverse imagined audience and context collapse. Findings suggest that some of Duck’s relational dissolution model manifests on social media, particularly social, gravedressing, and resurrection processes. Users consider and capitalize on perceived affordances of computer-mediated communication channels to construct, curate, or avoid public accounts of their breakups. Our study also provides a methodological framework for investigating user experiences and selective self-presentation on social media over time synthesizing quantitative and qualitative methods.

ECG simulator with configurable skin-electrode impedance and artifacts emulation

Electrocardiograms (ECG) recorded from everyday objects, such as wearables, fitness machines or smart steering wheels are becoming increasingly common. Applications are diverse and include health monitoring, athletic performance optimization, identification, authentication, and entertainment. In this study we report the design and implementation of an innovative ECG simulator, providing simulation of signal related artifacts and a dynamically adjustable skin-electrode interface model. The ECG simulator includes a unique combination of features: emulation of time dependent skin-electrode impedance, adjustable differential and common-mode interference, generation of lead-off events and analog front-end output digitalization. The skin-electrode capacitance range is 1 nF-255 nF and the resistance span is 4 kΩ-996 kΩ. System’s functionality is demonstrated using a commercially available ECG front-end. The simulated SNR degradation introduced by the ECG simulator is under 0.1 dB. Results show that the skin-electrode interface can have a significant impact in the acquired waveforms. Impedance electrode imbalance, specifically of the resistive component, can generate artifacts which can be misinterpreted has arrhythmias. The proposed device can be useful for hardware and software ECG development and for training physicians and nurses to readily recognize skin-electrode impedance related artifacts.

BRIQUETAGE AND BRINE: LIVING AND WORKING AT THE CLASSIC MAYA SALT WORKS OF EK WAY NAL, BELIZE

AbstractSystematic flotation survey and spatial analysis of artifacts at the submerged salt work of Ek Way Nal reveal evidence of a residence, salt kitchens, and additional activities. Ek Way Nal is one of 110 salt works associated with a Late to Terminal Classic (A.D. 600–900) salt industry known as the Paynes Creek Salt Works. Wooden posts that form the walls of 10 buildings are remarkably preserved in a peat bog below the sea floor providing an opportunity to examine surface artifacts in relation to buildings. Numerous salt kitchens have been located at the Paynes Creek Salt Works by evidence of abundant briquetage—pottery associated with boiling brine over fires to make salt. As one of the largest salt works with 10 buildings, there is an opportunity to examine variability in building use. Systematic flotation survey over the site and flagging and mapping individual artifacts and posts provide evidence that the Ek Way Nal salt makers had a residence near the salt kitchens, along with evidence of salting fish for subsistence or surplus household production. The results are compared with ethnographic evidence from Sacapulas and other salt works.

Project Recuerdo: Honoring Latinx Families’ Knowledge Within the School

AbstractThe authors describe a culturally sustaining bilingual family engagement project that draws upon Latinx families’ experiential and cultural wealth and integrates that knowledge within the literacy curriculum of a bilingual fourth grade classroom. Through the use of monthly writing prompts, Project Recuerdo, engages families in sharing stories that demonstrate cultural, linguistic, and historical knowledge with the child, teacher, and wider community. This form of family engagement counters deficit orientations towards diverse families, especially Mexican American families, as problems to fix, and instead honors the wealth of knowledge families have and integrates it within the curriculum. Through the analysis of the bilingual journal entries, related classroom artifacts, and family focal groups, the authors validate the importance of learning with and from diverse families; and detail the process for planning the implementation of the family project. Authors provide suggestions for teacher self‐reflection and possible writing prompts to engage families.

Designing Debt Payment Standard Operating Procedures in the SMEs Retail Industry Using Business Process Modeling and Notation (BPMN): A Case Study of a Retailer in East Java, Indonesia

The application of standard operating procedures on the micro, small, and medium enterprise retail industry was critical since this type of enterprise employs the majority of national workforces and has become the most significant sector in Indonesia's economic growth. The purpose of this study was to investigate the business process and develop standard operating procedures for the debt payment process at one of the representative retailers in East Java Province, Indonesia, PO Dolopo Grosir. This study was part of a descriptive and qualitative study. Interviews and observations were also used to obtain data. According to the research, the development of a business process diagram would be the standard operating procedure during the debt payment process. Business Process Modeling develops this SOP creation activity further by adding several related artifacts such as data and business rules. The business process model modeled with BPMN can be used by parties who understand technical matters to be translated into information system needs.

101 MRI Brain Solutions, 1st Edition: A Book Review

This book is written by a group of Neuroradiologists from an Indian university and published by Jaypee Brothers Medical Publishers (P) Ltd see (Figure 1). The first chapter discusses the physical principles of MRI and the 2nd chapter illustrates brain anatomy. From the 3rd to 11th chapter, all chapters discuss different malformations and disorders that affect the brain. Chapters 12th and 13th are glossary and acronyms respectively. The only colored pictures are in the plate and the rest of the book illustrations has no colors. Each chapter is written by a Neuroradiologists of the 14 authors of the book (3 editors and 11 contributors). The used method in 3rd to 11th chapter is a presentation of a case as an example of the brain malformation or disorder on an MRI scan. The book uses Radioland’s style in presenting the cases. Each case will have a case presentation and history, MRI scan pictures, MRI findings, comments and explanations, opinions, and clinical discussion. This book is (101), so it is for beginners and it does not cover all MRI neuroradiology topics since it has 101 cases only. The book has too many English language mistakes and a significant lack of proofreading. Some of the MRI images have poor image quality. The book is printed on high-quality papers. In some chapters of the book, there are some CT scans to show the difference between MRI and CT in the ability to show some of the abnormalities. The medical illustration is not high-quality illustration; for example; the Percheron artery was illustrated in the book poorly. Nobody should expect to see professional illustrations like Netter’s style in illustrations in this book. In the book, they rarely use arrows to indicate the location of the pathology. The book does not mention some of the famous neuroradiology signs. In the subdural hematoma case, they present a case of acute on chronic hematoma as subdural hematoma case which would be better to show acute in one case, chronic in one case, and acute on chronic on a third case because this book is for beginners. Some anatomical illustrations are out of the chapter which discuss the anatomy of the brain like the illustration of the cerebral venous system on page 137, figure 28. From page 139 to 144, the book presents three anatomical variations in the brain’s vasculatures (carotid cavernous fistula, persistent occipital sinus, and fetal posterior cerebellar artery) which would be better to be in a separate chapter about anatomical variations. Sometimes, the book will mention a famous neuroradiology sign without providing any MRI image as a demonstration. As well, the book will describe some findings which is invisible on MRI images and the authors will write “not seen in these images”. If the finding is not demonstrated for the readers, the authors should not mention it in the findings. Instead, they can include this undemonstrated finding in the comments and explanation section of the case. This book will mention too many things (radiological signs, findings, associated conditions, etc.) without showing figures for what they are writing about like in the astrocytoma case they mention astrocytoma’s types without differentiating them on figures. Plus, the cases are not mentioned in an organized fashion. For example, the book will speak about a tumor that affects a specific region (let’s call it region number 1) then they will write about another tumor in a different region (let’s call it region number 2) then they jump back to the first region and write about another tumor that affects region number 1. The book needs to be organized to write; for example; the tumors in cerebellopontine angle together which will help the reader to collect and compare all the information about the tumors that affect this region then move to another region. The book will provide a low image quality with too many artifacts; for example; the diffusion image in the hypoglycemia case. The artifacts chapter discusses only three common types of artifacts which are the Gibbs phenomenon, zipper artifact, and susceptibility artifact. The chapter can be improved by organizing the artifacts like; patient-related, signal processing related, and machinery (hardware) related artifacts. The artifacts’ chapter is placed in between clinical cases which should be removed to the beginning or at the end of the book. The last chapter collected different cases under miscellaneous.

Reframing Art with Nature: Flowers, People, and Art in Bloom

In extending Bernard Stiegler’s conceptualizations of life as the economy of death and Alexander Marshack’s historical tracings of early-human artifacts in relation to flowers, I strive to situate and read flowers as media that they carry an embedded history and infrastructure that reflects and challenges the anthropocentrism that has cultivated, commodified, and curated blooms throughout time. In looking to theorists such as Donna Haraway and Jane Bennett, I study a specific event in which flowers are presented to the public as art: the North Carolina Museum of Art’s Art in Bloom. Art in Bloom offers and sustains a complex media ecology, where paintings and sculptures readily and more permanently adorn the gallery spaces, living blooms are used as accompanying pieces of floral art for four days a year, text embeds all signifying information through the museum, money gains admittance to the space, and visitors experience the collective forces of mediation – and contribute to it by documenting their experience through personal digital photography. Such a study of flowers as both media and art must simultaneously recognize the humanist structures blooms are cultivated and commodified within, emphasizing Art in Bloom as a prime instance in which the tensions surrounding nature, gender, art, and media collide – and where traditional perceptions and understandings of what constitutes art is deconstructed and reverted for the human-oriented benefit and economic gains. Article received: April 20, 2021; Article accepted: June 21, 2021; Published online: September 15, 2021; Original scholarly paper

Generative adversarial learning for improved data efficiency in underwater target classification

In the realms of the ocean, it becomes a formidable task to detect and classify the passive acoustic targets from the convoluted acoustic mixture confronted by the sonar frontend. Though the advances in deep learning driven by enormity of data and computational infrastructure have resulted in a tremendous leap in performance across various domains, passive sonar target recognition still remains an elusive task for the acoustic as well as signal processing communities. Various channel related artifacts together with the inherent difficulty in obtaining annotated data limit the target records required for training these massive supervised networks so as to yield an optimal performance. This demands models that can generalize well beyond the often sparse training instances. In order to address this issue, generative frameworks can be utilized to model the causal attributes of the target signature so that the network becomes tolerant to the distortions induced by the ambient noise and channel artifacts. This paper exploits the generative modelling capability of an Auxiliary Classifier Generative Adversarial Network (ACGAN) to construct a data-efficient underwater target classifier. These class-conditioned frameworks based on unsupervised representation learning can model the true data distribution using the latent attributes of the training data. In order to make the causal factors of variation more explicit, the raw time domain samples are transformed into joint time–frequency representations using filterbanks initialized at different perceptual scales. Experimental evaluation of the proposed system on target instances collected from diverse locations of the Indian Ocean yields promising results in terms of data efficiency, class confidence and classification accuracy.

Multimodality imaging in the diagnosis and management of prosthetic valve endocarditis: A contemporary narrative review.

Infective endocarditis is one of the leading life-threatening infections around the world. With the exponential growth in the field of transcatheter interventions and advances in specialized surgical techniques, the number of prosthetic valves and cardiac implantable devices has significantly increased. This has led to a steep rise in the number of cases of prosthetic valve endocarditis (PVE) comprising up to 30% of all cases. Clinical guidelines rely on the use of the modified Duke criteria; however, the diagnostic sensitivity of the modified Duke criteria is reduced in the context of PVE. This is in part attributed to prosthesis related artifact which greatly affects the ability of echocardiography to detect early infective changes related to PVE in certain cases. There has been increasing recognition of the roles of complementary imaging modalities and updates in international society recommendations. Prompt diagnosis and treatment can prevent the devastating consequences of this condition. Imaging modalities such as cardiac computed tomography and 18-fluorodeoxyglucose positron emission tomography/computed tomography are diagnostic tools that provide a complementary role to echocardiography in aiding diagnosis, pre-operative planning, and treatment decision-making process in these challenging cases. Understanding the strengths and limitations of these adjuvant imaging modalities is crucial for the implementation of appropriate imaging modalities in clinical practice.

Rewarding Participation in Social Media Enabled Communities of Practice

Tacit knowledge is difficult to objectify, whether the goal of doing so is to test, share, or technologically reproduce it. Therefore, extending the traditionally skills-based I.T. certification practice to the assessment of social learning that occurs in Communities of Practice will be a challenge. My research approaches this challenge by examining the role of social media and related technologies, information systems, and artifacts in the mediation of knowledge and expertise across the boundary between workplace-based Communities of Practice and external professional communities. Findings from this empirical case study of the Microsoft MVP Award implicate certain design considerations into the design of social media within the workplace.

Integration of Museum User Behavior Information Based on Wireless Network

Online museum information resource systems are getting popular these days which allow the users to get detailed information about the objects of their interest, and the user preferences are stored to search for related artifacts considering his/her online behavior. The behavior of users browsing online is integrated to capture relevant information which is integrated into museum information resources. Unfortunately, present implementations have errors in integration and optimization system, so a wireless network-based museum user behavior information integration system is proposed to calculate the user’s interest in museum’s cultural relics. The user behavior information resource model is developed based upon the degree of user interest, and forgetting functions with different decay rates are employed to describe changes in the interest level. This information is then used to construct users’ interest matrices. This matrix also contains information regarding the cultural relics that users have not yet visited. The system will introduce the interest weights of feature words to take the top features of the user behavior information for the integration of the users’ behavior and to combine the feature vectors that can represent the overall trajectory. Moreover, those feature vectors are described that can represent the local trajectory into feature vector to identify the slow-moving sparse targets, which is then utilized for the integration of users’ behavior information. The simulation tests prove that the proposed method can achieve low error in the integration process of user behavior information resources, thereby yielding good results.

Application of a SCOBA in Educational Praxis of L2 Written Argumentative Discourse

The purpose of this study was to examine if and the way in which a central argumentative discourse schema, as a cognitive tool, was appropriated by an English language learner. There has been little research on the development of L2 written argumentative discourse after a period of instruction and no study, to my knowledge, examining and detailing a systematic pedagogy for L2 learners. Grounded in both C-BLI (concept-based language instruction) and cognitive-process theory of writing (Bereiter and Scardamlaia, 1987), the present study details the appropriation of a central Toulmin (1958/2003) SCOBA, ‘schema for complete orientating basis of an action,’ (Gal’perin, 1989: 70) to mediate the cognitive processes leading to the production of texts that feature argumentative discourse features. The central Toulmin SCOBA and the text generation artifacts that were (co-) constructed during C-BLI will be examined and evidence will be provided for the effectiveness of the SCOBA. There will be a theoretical and empirical discussion of how the SCOBA and its related artifacts made the-rule-of thumb (Negueruela, 2003) and amorphous idea (Vygotsky, 1986) of thesis-support scientific and discrete. In order to guide the teaching-learning of written argumentative discourse, the cognitive processes of writing were conceptualized as mental actions (Gal’perin, 1989). The findings indicate that the learner’s cognitive processes of composing and the quality of his texts improved during and after instruction.

Can Hybrid Arterial Spin Labeling-Tagged Zero-Echo-Time Magnetic Resonance Angiography Be an Effective Candidate in the Evaluation of Intracranial Artery Diseases? A Clinical Feasibility Study.

Flow related artifacts in continuous arterial spin labeling (cASL) zero-echo-time (ZTE) magnetic resonance angiography (MRA) could influence the vasculature visualization. To investigate the clinical feasibility for the intracranial artery diseases assessment by utilizing hybrid ASL-ZTE-MRA (hASL-ZTE-MRA). Prospective, technical development. Sixty-seven subjects with known/suspected cerebrovascular diseases. Gradient echo based cASL-/hASL- ZTE-MRA at 3.0 T. Subjective/objective evaluation for sound-levels. Image quality (IQ), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were analyzed within artery segments. Stenotic grading, aneurysm measurement, and signal intensity of lesions were further analyzed. Kolmogorov-Smirnov test for data normality check. Between two MRAs: Wilcoxon signed-rank test for sound experience/IQ ratings analysis; Paired t test for SNR/CNR comparison. One-way analysis of variance for sound intensity comparison. For stenosis grading/aneurysm measurement: Kendall's W test/intraclass correlation coefficient (ICC) for interobserver agreement test within each modality, weighted kappa statistics/ICC for intermodality agreement test between each MRA and computed tomography angiography. Sound-level perception/intensity was similar (P=0.86, P=0.55) between MRAs. The mean IQ score for hASL-ZTE-MRA was on diagnostic scale and slightly higher (P < 0.05) than that of cASL-ZTE-MRA. hASL-ZTE-MRA provided higher (P < 0.05) SNR/CNR than that of cASL-ZTE-MRA. Signal uniformity was improved on hASL-ZTE-MRA, particularly among the anterior circulation (P < 0.05). Comparing to cASL-ZTE-MRA, on hASL-ZTE-MRA, stenotic lesions were accurately assessed; flow in the stent or aneurysm remnant was better depicted (P < 0.05); AVM nidus was preferred with increased SNR (P < 0.05). No significant differences for the aneurysm measurement were found between MRAs (P=0.95), in addition to the slightly higher SNR (P < 0.05) on hASL-ZTE-MRA. Comparing to cASL-ZTE-MRA, hASL-ZTE-MRA is robust and feasible for the evaluation of intracranial artery diseases with diagnostic IQ, improved vessel contrast, and better signal heterogeneity. 2 TECHNICAL EFFICACY: 2.

An ontological analysis of software system anomalies and their associated risks

Software systems have an increasing value in our lives, as our society relies on them for the numerous services they provide. However, as our need for larger and more complex software systems grows, the risks involved in their operation also grows, with possible consequences in terms of significant material and social losses. The rational management of software defects and possible failures is a fundamental requirement for a mature software industry. Standards, professional guides and capability models directly emphasize how important it is for an organization to know and to have a well-established history of failures, errors and defects as they occur in software activities. The problem is that each of these reference models employs its own vocabulary to deal with these phenomena, which can lead to a deficiency in the understanding of these notions by software engineers, causing potential interoperability problems between supporting tools, and, consequently, a poorer adoption of these standards and tools in practice. In this paper, we address this problem of the lack of a consensual conceptualization in this area by proposing two reference conceptual models: an Ontology of Software Defects, Errors and Failures (OSDEF), which takes into account an ecosystem of software artifacts, and a Reference Ontology of Software Systems (ROSS), which characterizes software systems and related artifacts at different levels of abstraction. Moreover, we use OSDEF and ROSS to perform an ontological analysis of the impact of defects, errors and failures of software systems from a risk analysis perspective. To do that, we employee an existing core ontology, namely, the Common Ontology of Value and Risk (COVR). The ontologies presented here are grounded on the Unified Foundational Ontology (UFO) and based on well-known and widely-accepted standards, professional and scientific guides and capability models. We demonstrate how this approach can suitably promote conceptual clarification and terminological harmonization in this area.

Reduction of microwave ablation needle related metallic artifacts using virtual monoenergetic images from dual-layer detector spectral CT in a rabbit model with VX2 tumor

The purpose of the study was to investigate the application of virtual monoenergetic images (VMIs) in reducing metal artifacts in rabbit VX2 liver cancer models treated with microwave ablation (MWA) therapy. A total of 31 VX2 liver cancer models that accepted CT-guided percutaneous microwave ablation were analyzed. Conventional images (CIs) with the most severe metallic artifacts and their corresponding energy levels from 40 to 200 keV with 10 keV increment of VMIs were reconstructed for further analysis. Objective image analysis was assessed by recording the attenuation (HU) and standard deviation of the most severe hyper/hypodense artifacts as well as artifact-impaired liver parenchyma tissue. Two radiologists visually evaluated the extent of artifact reduction, assessed data obtained by a diagnostic evaluation of liver tissues, and appraised the appearance of new artifacts according to the grade score. Statistical analysis was performed to compare the difference between CIs and each energy level of VMIs. For subjective assessment, reductions in hyperdense and hypodense artifacts were observed at 170–200 keV and 160–200 keV, respectively. The outcomes of the diagnostic evaluation of adjacent liver tissue were statistically higher at 140–200 keV for VMIs than for CIs. In terms of objective evaluation results, VMIs at 90–200 keV reduced the corrected attenuation of hyperdense and of artifact-impaired liver parenchyma compared with CIs (P < 0.001). When VMIs at 80–200 keV decreased the hypodense artifacts (P < 0.001). Therefore, we concluded that VMIs at 170–200 keV can obviously decrease the microwave ablation needle-related metal artifacts objectively and subjectively in rabbit VX2 liver cancer models.

Sound artefacts as containers. The materiality of rhythm in ancient Mesoamerica

This paper focuses on the role played by rhythmic instruments in Aztec ritual performances, combining the study of sound related artefacts as primary archaeological record with other contextual sources, using a multidisciplinary approach. Two categories of Aztec percussion instruments (huehuetl and teponaztli) will be analyzed, trying to get closer to the emic point of view, the indigenous concept of drums as containers of non-human entities. This will offer a better understanding of their role within the ceremonial context. Another important aspect here stressed is the importance of considering the materiality of these sound related artefacts, entangled with humans in a dialogical way to shape the ritual soundscape. Finally, a brief excursion in ethnography, will show how ancient percussion instruments are today re-signified in a totally changed ritual context, where their enduring materiality becomes a field of negotiation and claim of identity for the members of indigenous communities.