Miracle-dz/UniFAR-FTUs huggingface dataset:
Blood vessel segmentation in modern wide-field retinal images in the presence of additive Gaussian noise

Abstract. Retinal blood vessels indicate some serious health ramifications, such as cardiovascular disease and stroke. Thanks to modern imaging technology, high-resolution images provide detailed information to help analyze retinal vascular features before symptoms associated with such conditions fully develop. Additionally, these retinal images can be used by ophthalmologists to facilitate diagnosis and the procedures of eye surgery. A fuzzy noise reduction algorithm was employed to enhance color images corrupted by Gaussian noise. The present paper proposes employing a contrast limited adaptive histogram equalization to enhance illumination and increase the contrast of retinal images captured from state-of-the-art cameras. Possessing directional properties, the multistructure elements method can lead to high-performance edge detection. Therefore, multistructure elements-based morphology operators are used to detect high-quality image ridges. Following this detection, the irrelevant ridges, which are not part of the vessel tree, were removed by morphological operators by reconstruction, attempting also to keep the thin vessels preserved. A combined method of connected components analysis (CCA) in conjunction with a thresholding approach was further used to identify the ridges that correspond to vessels. The application of CCA can yield higher efficiency when it is locally applied rather than applied on the whole image. The significance of our work lies in the way in which several methods are effectively combined and the originality of the database employed, making this work unique in the literature. Computer simulation results in wide-field retinal images with up to a 200-deg field of view are a testimony of the efficacy of the proposed approach, with an accuracy of 0.9524.
Adaptive Random Network Coding in WiMAX

The IEEE 802.16 standard, or WiMAX, has emerged as one of the strongest contenders for broadband wireless access technology. In our previous work, we proposed a protocol using random network coding in WiMAX MAC layer, which has indeed offered important advantages. In this paper, we propose adaptive random network coding in WiMAX by introducing two algorithms in order to further improve the performance. First, we utilize the channel state information feedback to dynamically construct the packets that could be better matched to the fluctuating channel conditions, so as to obtain a higher throughput. Second, we design the algorithm by adapting the number of upstream nodes, which helps to minimize the overhead of sender push of redundant coded blocks to the receiver even after the receiver has completely received the data segment. Coupled with random network coding, both algorithms offer salient performance improvement as evidenced in our simulation evaluation.
Grid benchmarking: vision, challenges, and current status

Grid benchmarking is an important and challenging topic of Grid computing research. In this paper, we present an overview of the key challenges that need to be addressed for the integration of benchmarking practices, techniques, and tools in emerging Grid computing infrastructures. We discuss the problems of performance representation, measurement, and interpretation in the context of Grid benchmarking, and propose the use of ontologies for organizing and describing benchmarking metrics. Finally, we present a survey of ongoing research efforts that develop benchmarks and benchmarking tools for the Grid. Copyright © 2006 John Wiley & Sons, Ltd.
Missed diagnoses of acute myocardial infarction in the emergency department: variation by patient and facility characteristics

Abstract Background: An estimated 1.2 million people in the US have an acute myocardial infarction (AMI) each year. An estimated 7% of AMI hospitalizations result in death. Most patients experiencing acute coronary symptoms, such as unstable angina, visit an emergency department (ED). Some patients hospitalized with AMI after a treat-and-release ED visit likely represent missed opportunities for correct diagnosis and treatment. The purpose of the present study is to estimate the frequency of missed AMI or its precursors in the ED by examining use of EDs prior to hospitalization for AMI. Methods: We estimated the rate of probable missed diagnoses in EDs in the week before hospitalization for AMI and examined associated factors. We used Healthcare Cost and Utilization Project State Inpatient Databases and State Emergency Department Databases for 2007 to evaluate missed diagnoses in 111,973 admitted patients aged 18 years and older. Results: We identified missed diagnoses in the ED for 993 of 112,000 patients (0.9% of all AMI admissions). These patients had visited an ED with chest pain or cardiac conditions, were released, and were subsequently admitted for AMI within 7 days. Higher odds of having missed diagnoses were associated with being younger and of Black race. Hospital teaching status, availability of cardiac catheterization, high ED admission rates, high inpatient occupancy rates, and urban location were associated with lower odds of missed diagnoses. Conclusions: Administrative data provide robust information that may help EDs identify populations at risk of experiencing a missed diagnosis, address disparities, and reduce diagnostic errors.
A Frameshift Mutation at Gly975 in the Transmembrane Domain of GPIIb Prevents GPIIb-IIIa Expression – Analysis of Two Novel Mutations in a Kindred with Type I Glanzmann Thrombasthenia

Summary Two Hispanic siblings presenting with lifelong mucocutaneous bleeding were diagnosed clinically with Glanzmann thrombasthenia on the basis of a normal platelet count, prolonged bleeding time and absent platelet aggregation in response to multiple agonists. Quantitative analysis of the probands’ platelets by flow cytometry showed a complete absence of GPIIb-IIIa, consistent with Type I thrombasthenia. Genetic analysis showed the probands to be compound heterozygotes for two novel mutations of GPIIb: a C1414>G mutation in exon 14, resulting in a premature termination codon replacing residue Tyr440, and the insertion of a G at position 3016 in exon 29, leading to a frameshift affecting the C-terminal half of the transmembrane domain and the cytoplasmic tail. The frameshifted sequence alters residues from Gly975 onwards and is predicted to significantly alter the hydro-pathy and charge profiles of the GPIIb transmembrane domain. The Type I phenotype associated with this mutation suggests that GPIIb residues 975-1008 contain critical structural motifs for heterodimer assembly, membrane retention, export from the ER and surface expression.
Higher mortality of adults with asthma: A 15‐year follow‐up of a population‐based cohort

Higher all‐cause mortality in asthmatics has been shown previously. Polysensitization is associated with higher morbidity among asthmatic children, and allergic rhinitis and/or allergic conjunctivitis (AR/AC) are associated with higher morbidity in adult asthmatics. Little is known about the effect of AR/AC and other factors on mortality among adult asthmatics. The aim was to study mortality and its risk factors in adults with and without asthma.
Urinary MicroRNA as Biomarker in Renal Transplantation

Urine represents a noninvasive source in which proteins and nucleic acids can be assessed. Such analytes may function as biomarkers to monitor kidney graft pathology at every desired frequency, thereby providing a time window to prevent graft damage by therapeutic intervention. Recently, several proteins have been measured in urine as markers of graft injury. However, the specificity is limited, and measuring urinary proteins generally lacks the potential to predict early kidney graft damage. Currently, urinary mRNA and microRNA are being investigated to evaluate the prognostic value of changes in gene expression during the initial stages of graft damage. At such time point, a change in treatment regimen and dosage is expected to have maximum potency to minimize future decline in graft function. Both mRNA and microRNAs have shown promising results in both detection and prediction of graft injury. An advantage of microRNAs compared to mRNA molecules is their stability, a characteristic that is beneficial when working with urine samples. In this review, we provide the current state of urinary biomarkers in renal transplantation, with a focus on urinary microRNA. In addition, we discuss the methods used to study urinary microRNA expression.
Survey on the impact of fingerprint image enhancement

The performance of fingerprint comparison algorithms depends on the reliability and accuracy of the features extracted from the fingerprints. The accuracy of the feature extraction algorithms is assumed to depend on the quality of the fingerprint images. Especially, low-quality images can be challenging for feature extraction algorithms. Image enhancement may allow to extract features more accurately. There is a lack of extensive and quantitative evaluation of image enhancement methods. This study investigates the impact of seven typical image enhancement methods on biometric sample quality and on biometric performance. The interrelation of image quality and biometric performance is investigated on 14 datasets. Biometric quality measures are estimated based on image quality metrics NFIQ1 and NFIQ2.0. Biometric performance is tested using MINDTCT and FingerJetFX for feature extraction and BOZORTH3 for biometric comparison. This work shows that the biometric performance can be improved by image enhancement. The significance of improvements depends on both the quality of the datasets and the feature extraction. Thus, there is no single best improvement algorithm. A correlation of changes in scores and image qualities can only be found on the level of entire datasets. No significant correlation can be found for single biometric comparisons.
Online Fault Identification of Digital Hydraulic Valves Using a Combined Model-Based and Data-Driven Approach

Robustness and fault-tolerance are desirable properties for hydraulic working machines and field robots. In applications where service personnel do not have easy access to the machine, it is important that the machine can continue its operation despite single machinery faults. Digital hydraulics enables a design which is inherently fault-tolerant by having each hydraulic actuator controlled by a number of parallel on/off valves. The exact state operation of a digital hydraulic system enables model based diagnostics of the hydraulic components and the possibility to compensate for identified faults. This paper presents an approach for identifying faulty valves based on combination of pressure measurements made during the normal operation of the machine and a mathematical model describing the flow balance of the hydraulic system.
Interactive visualization for scar transmurality in cardiac resynchronization therapy

Heart failure is a serious disease affecting about 23 million people worldwide. Cardiac resynchronization therapy is used to treat patients suffering from symptomatic heart failure. However, 30% to 50% of patients have limited clinical benefit. One of the main causes is suboptimal placement of the left ventricular lead. Pacing in areas of myocardial scar correlates with poor clinical outcomes. Therefore precise knowledge of the individual patient’s scar characteristics is critical for delivering tailored treatments capable of improving response rates. Current research methods for scar assessment either map information to an alternative non-anatomical coordinate system or they use the image coordinate system but lose critical information about scar extent and scar distribution. This paper proposes two interactive methods for visualizing relevant scar information. A 2-D slice based approach with a scar mask overlaid on a 16 segment heart model and a 3-D layered mesh visualization which allows physicians to scroll through layers of scar from endocardium to epicardium. These complementary methods enable physicians to evaluate scar location and transmurality during planning and guidance. Six physicians evaluated the proposed system by identifying target regions for lead placement. With the proposed method more target regions could be identified.
Variable impairment of platelet functions in patients with severe, genetically linked immune deficiencies

In patients with dysfunctions of the Ca2+ channel ORAI1, stromal interaction molecule 1 (STIM1) or integrin-regulating kindlin-3 (FERMT3), severe immunodeficiency is frequently linked to abnormal platelet activity. In this paper, we studied platelet responsiveness by multiparameter assessment of whole blood thrombus formation under high-shear flow conditions in 9 patients, including relatives, with confirmed rare genetic mutations of ORAI1, STIM1 or FERMT3. In platelets isolated from 5 out of 6 patients with ORAI1 or STIM1 mutations, store-operated Ca2+ entry (SOCE) was either completely or partially defective compared to control platelets. Parameters of platelet adhesion and aggregation on collagen microspots were impaired for 4 out of 6 patients, in part related to a low platelet count. For 4 patients, platelet adhesion/aggregation and procoagulant activity on von Willebrand Factor (VWF)/rhodocytin and VWF/fibrinogen microspots were impaired independently of platelet count, and were partly correlated with SOCE deficiency. Measurement of thrombus formation at low shear rate confirmed a greater impairment of platelet functionality in the ORAI1 patients than in the STIM1 patient. For 3 patients/relatives with a FERMT3 mutation, all parameters of thrombus formation were strongly reduced regardless of the microspot. Bone marrow transplantation, required by 2 patients, resulted in overall improvement of platelet function. We concluded that multiparameter assessment of whole blood thrombus formation in a surface-dependent way can detect: i) additive effects of low platelet count and impaired platelet functionality; ii) aberrant ORAI1-mediated Ca2+ entry; iii) differences in platelet activation between patients carrying the same ORAI1 mutation; iv) severe platelet function impairment linked to a FERMT3 mutation and bleeding history.
Spectral Radii of Asymptotic Mappings and the Convergence Speed of the Standard Fixed Point Algorithm

Important problems in wireless networks can often be solved by computing fixed points of standard or contractive interference mappings, and the conventional fixed point algorithm is widely used for this purpose. Knowing that the mapping used in the algorithm is not only standard but also contractive (or only contractive) is valuable information because we obtain a guarantee of geometric convergence rate, and the rate is related to a property of the mapping called modulus of contraction. To date, contractive mappings and their moduli of contraction have been identified with case-by-case approaches that can be difficult to generalize. To address this limitation of existing approaches, we show in this study that the spectral radii of asymptotic mappings can be used to identify an important subclass of contractive mappings and also to estimate their moduli of contraction. In addition, if the fixed point algorithm is applied to compute fixed points of positive concave mappings, we show that the spectral radii of asymptotic mappings provide us with simple lower bounds for the estimation error of the iterates. An immediate application of this result proves that a known algorithm for load estimation in wireless networks becomes slower with increasing traffic.
Decentralized closing ranks in vehicle formations and sensor networks

In this paper, we present recent results on the closing ranks problem in vehicle formations and sensor networks. The closing ranks problem is to determine new sensing/communication links in the event of agent failure in order to recover certain properties of the underlying information architecture. We model the information architecture as a graph G(V, E), where V is a set of vertices representing the agents and E is a set of edges representing information flow amongst the agents. We focus on two properties of the graph called rigidity and global rigidity, which are required for formation shape maintenance and sensor network self-localization, respectively. We show that while previous results permit local repair involving only neighbours of the lost agent, the repair cannot always be implemented using only local information. Utilizing a graph theoretic substitution principle, we present new results that can be applied to make the local repair using only local information. We also describe implementation of the solution and illustrate the ideas through examples.
Predictors of Residential Mobility among Older Canadians and Impact on Analyses of Place and Health Relationships

This study aimed to identify predictors of residential mobility in 55+ Canadians, to characterise neighbourhood changes following mobility, to assess whether such changes differ according to income, and to evaluate for cross-sectional estimations of place-health relationships the extent of bias associated with residential mobility. Using longitudinal data from the Canadian National Population Health Study (NPHS), residential mobility was operationalised by a change in postal code between two consecutive waves. Individuals' sociodemographic factors and neighbourhood characteristics were analysed in relation to mobility. Bias in cross-sectional estimations of place-health associations was assessed analysing neighbourhood-level deprivation and housing quality in relation to self-assessed health. Multiple age-related events were predictive of moving. Three out of 10 individuals moved at least once. Two thirds of movers experienced a change in neighbourhood type and such changes were not associated with income. No systematic biases in estimating place effects on health using cross-sectional data were observed. Given that individual-level socioeconomic status (SES) was neither a predictor of moving nor of its consequences in terms of neighbourhood type, controlling for SES could potentially lead to biased estimations of place-health associations. Results suggest that cross-sectional data can yield valid estimations of place-health associations among older adults.
Influence of longitudinal position on the evolution of steady-state signal in cardiac cine balanced steady-state free precession imaging

Background Emerging quantitative cardiac magnetic resonance imaging (CMRI) techniques use cine balanced steady-state free precession (bSSFP) to measure myocardial signal intensity and probe underlying physiological parameters. This correlation assumes that steady-state is maintained uniformly throughout the heart in space and time. Purpose To determine the effects of longitudinal cardiac motion and initial slice position on signal deviation in cine bSSFP imaging by comparing two-dimensional (2D) and three-dimensional (3D) acquisitions. Material and Methods Nine healthy volunteers completed cardiac MRI on a 1.5-T scanner. Short axis images were taken at six slice locations using both 2D and 3D cine bSSFP. 3D acquisitions spanned two slices above and below selected slice locations. Changes in myocardial signal intensity were measured across the cardiac cycle and compared to longitudinal shortening. Results For 2D cine bSSFP, 46% ± 9% of all frames and 84% ± 13% of end-diastolic frames remained within 10% of initial signal intensity. For 3D cine bSSFP the proportions increased to 87% ± 8% and 97% ± 5%. There was no correlation between longitudinal shortening and peak changes in myocardial signal. The initial slice position significantly impacted peak changes in signal intensity for 2D sequences (P < 0.001). Conclusion The initial longitudinal slice location significantly impacts the magnitude of deviation from steady-state in 2D cine bSSFP that is only restored at the center of a 3D excitation volume. During diastole, a transient steady-state is established similar to that achieved with 3D cine bSSFP regardless of slice location.
Large-Scale Data Collection in Online Social Networks

The popularity and huge amount of information published in Online Social Networks (OSN) established them as one of the main data sources for a variety of research community fields. However, the design of a large-scale dataset collection campaign is a major problem for organizations and researchers who aim in addressing their research questions by analyzing this type of data. OSN platforms provide Application Programming Interfaces (API) to third party developers, which enable them to retrieve and use this data for applications deployment. However, due to OSN imposed limitations, the process of retrieving large scale data with the use of these APIs is challenging and time consuming, resulting in datasets which are either incomplete or outdated. It is relatively impossible for an individual scientist or research group to follow an efficient dataset collection procedure and build a large sample in a short amount of time. In this paper we present a framework for efficient crowd crawling of OSN. Our framework is based on the use of multiple OSN accounts, which are engaged in an efficient distributed collection process able to circumvent the imposed limitations without violating the terms of use. We present an evaluation of the proposed solution and demonstrate its performance in terms of dataset completeness and timeliness, for the case study of Twitter, one of the most popular platforms used in research.
Generalized linear dynamic factor models - An approach via singular autoregressions

We consider generalized linear dynamic factor models. These models have been developed recently and they are used for high dimensional time series in order to overcome the “curse of dimensionality”. We present a structure theory with emphasis on the zeroless case, which is generic in the setting considered. Accordingly the latent variables are modeled as a possibly singular autoregressive process and (generalized) Yule Walker equations are used for parameter estimation.
PTSD and dissociation symptoms as mediators of the relationship between polyvictimization and psychosocial and behavioral problems among justice-involved adolescents

ABSTRACT Polyvictimization (PV) has been shown to be associated with psychosocial and behavioral impairment in community and high risk populations, including youth involved in juvenile justice. However, the mechanisms accounting for these adverse outcomes have not been empirically delineated. Symptoms of posttraumatic stress disorder (PTSD) and dissociation are documented sequelae of PV and are associated with a wide range of behavioral/emotional problems. This study used a cross-sectional research design and bootstrapped multiple mediation analyses with self-report measures completed by a large sample of justice-involved youth (N = 809, ages 12–19 years old, 27% female, 46.5% youth of color) to test the hypothesis that PTSD and dissociation symptoms mediate the relationship between PV and problems with anger, depression/anxiety, alcohol/drug use, and somatic complaints after controlling for the effects of exposure to violence and adversities related to juvenile justice involvement. As hypothesized, PTSD symptoms mediated the relationship of PV with all outcomes except alcohol/drug use problems (which had an unmediated direct association with PV). Partially supporting study hypotheses, dissociation symptoms mediated the relationship between PV and internalizing problems (i.e., depression anxiety; suicide ideation). Implications are discussed for prospective research demarcating the mechanisms linking PV and adverse outcomes in juvenile justice and other high risk populations.