18 research outputs found
Graph Theoretical Analysis of local ultraluminous infrared galaxies and quasars
We present a methodological framework for studying galaxy evolution by
utilizing Graph Theory and network analysis tools. We study the evolutionary
processes of local ultraluminous infrared galaxies (ULIRGs) and quasars and the
underlying physical processes, such as star formation and active galactic
nucleus (AGN) activity, through the application of Graph Theoretical analysis
tools. We extract, process and analyse mid-infrared spectra of local (z < 0.4)
ULIRGs and quasars between 5-38 microns through internally developed Python
routines, in order to generate similarity graphs, with the nodes representing
ULIRGs being grouped together based on the similarity of their spectra.
Additionally, we extract and compare physical features from the mid-IR spectra,
such as the polycyclic aromatic hydrocarbons (PAHs) emission and silicate depth
absorption features, as indicators of the presence of star-forming regions and
obscuring dust, in order to understand the underlying physical mechanisms of
each evolutionary stage of ULIRGs. Our analysis identifies five groups of local
ULIRGs based on their mid-IR spectra, which is quite consistent with the well
established fork classification diagram by providing a higher level
classification. We demonstrate how graph clustering algorithms and network
analysis tools can be utilized as unsupervised learning techniques for
revealing direct or indirect relations between various galaxy properties and
evolutionary stages, which provides an alternative methodology to previous
works for classification in galaxy evolution. Additionally, our methodology
compares the output of several graph clustering algorithms in order to
demonstrate the best-performing Graph Theoretical tools for studying galaxy
evolution.Comment: Accepted for publication in Astronomy and Computin
Worldwide survey of T2* cardiovascular magnetic resonance in Thalassaemia
Introduction
Thalassaemia major (TM) affects hundreds of thousands of patients worldwide but only a minority have access to regular blood transfusion and chelation therapy. Cardiovascular magnetic resonance (CMR) T2* measurement provides an accurate, reproducible measurement of cardiac iron which is the cause of heart failure and early death in many transfused TM patients. This technique has been adopted as part of routine management in many countries where survival is now approaching normal but little is known about the severity and effects of myocardial iron loading in different geographical regions.
Purpose
The aim of this study was to describe the burden of disease of myocardial siderosis (measured by T2*) in different populations throughout the world and to assess the relationship between T2* and outcome such as heart failure and cardiac death.
Methods
34 worldwide centres were involved in this survey of 3376 patients from Europe, the Middle East, North America, South America, North Africa, Australia and Asia. Anonymised data on myocardial T2* values were analysed in conjunction with clinical outcomes (heart failure and death).
Results
Overall, 57.5% of patients had no significant iron loading (T2* >20ms), 22.6% had moderate cardiac iron (10ms50%) in South-East Asia had cardiac iron (T2* >20ms) at baseline. At the time of the first scan, 100 patients (3.3%) had confirmed heart failure, the majority of whom (77.0%) had myocardial T2* <10ms with almost all (99%) having T2* <20ms. There were 113 patients who subsequently developed heart failure. 92.0% of these had T2* <10ms and 99.1% had a T2* <20ms. There were 39 deaths. Cardiac T2* values were <10ms in 79.5%, with 92.3% <20ms.
Conclusions
Even in this well-treated cohort with access to transfusion, chelation and CMR, there is a large proportion of TM patients with moderate to severe cardiac iron loading. Low T2* (<10ms) is associated with cardiac failure and death. There is a huge unmet worldwide need in terms of access to specialist medical care (including transfusion and chelation therapy) together with advanced monitoring techniques (such as CMR)
A Novel, Low-Volume Method for Organ Culture of Embryonic Kidneys That Allows Development of Cortico-Medullary Anatomical Organization
Here, we present a novel method for culturing kidneys in low volumes of medium that offers more organotypic development compared to conventional methods. Organ culture is a powerful technique for studying renal development. It recapitulates many aspects of early development very well, but the established techniques have some disadvantages: in particular, they require relatively large volumes (1–3 mls) of culture medium, which can make high-throughput screens expensive, they require porous (filter) substrates which are difficult to modify chemically, and the organs produced do not achieve good cortico-medullary zonation. Here, we present a technique of growing kidney rudiments in very low volumes of medium–around 85 microliters–using silicone chambers. In this system, kidneys grow directly on glass, grow larger than in conventional culture and develop a clear anatomical cortico-medullary zonation with extended loops of Henle
Training in infectious diseases across Europe in 2021 - a survey on training delivery, content and assessment
Objectives: To define the status of infectious diseases (ID) as an approved specialty in Europe; to enumerate the number of specialists (in general and in relation to the overall population) and specialist trainees and describe the content, delivery and evaluation of postgraduate training in ID in different countries.Methods: Structured web-based questionnaire surveys in March 2021 of responsible national authorities, specialist societies and individual country representatives to the Section of Infectious Diseases of the European Union for Medical Specialties. Descriptive analysis of quantitative and qualitative responses.Results:
In responses received from 33/35 (94.3%) countries, ID is recognized as a specialty in 24 and as a subspecialty of general internal medicine (GIM) in eight, but it is not recognized in Spain. The number of ID specialists per country varies from <5 per million inhabitants to 78 per million inhabitants. Median length of training is 5 years (interquartile range 4.0–6.0 years) with variable amounts of preceding and/or concurrent GIM. Only 21.2% of countries (7/33) provide the minimum recommended training of 6 months in microbiology and 30% cover competencies such as palliative care, team working and leadership, audit, and quality control. Training is monitored by personal logbook or e-portfolio in 75.8% (25/33) and assessed by final examinations in 69.7% (23/33) of countries, but yearly reviews with trainees only occur in 54.5% (18/33) of countries.Conclusions:
There are substantial gaps in modernization of ID training in many countries to match current European training requirements. Joint training with clinical microbiology (CM) and in multidisciplinary team working should be extended. Training/monitoring trainers should find greater focus, together with regular feedback to trainees within many national training programmes.peer-reviewe
Spinal ependymomas: Prognostic factors and treatment results
Objective: We retrospectively analyzed patients with spinal ependymomas who were treated in our institute. We correlated outcome and recurrence with clinical and pathological features.
Materials and Methods: Between January 2000 and January 2010, we treated 14 patients with spinal ependymoma (10 males, 4 females; mean age: 48.3±18 years, range: 18-79 years). All patients were operated and received standard postoperative care. The outcome was estimated based on Frankel scale.
Results: The most common presenting symptom was pain. All tumors were operated through a posterior approach and gross total resection was performed in 13/14 cases. Histopathological examination revealed the presence of one anaplastic ependymoma, nine grade II ependymomas, and four myxopapillary ependymomas. The mean Ki-67 index was 1.5%. All the patients were followed up postoperatively for an average of 5.1 years. One patient was reoperated because of recurrent disease and another received radiotherapy due to dissemination of disease. No association was found between extent of resection, tumor location, Ki-67 index, and recurrence of disease. There was a trend toward a higher risk of recurrence in myxopapillary ependymomas. Eight patients improved postoperatively. Interestingly, during the follow-up period, four patients developed a secondary neoplasia.
Conclusion: Early intervention and gross total resection of spinal ependymomas are associated with a favorable outcome. Further studies are needed to clarify the incidence of the development of a second cancer in these patients
Blood Glucose Levels May Aid the Decision for CT Scan in Minor Head Trauma
Traumatic brain injury has been associated with increased blood glucose levels. In the present study, we set out to investigate if blood glucose level in mild head trauma could predict the need for CT. One hundred fifty-nine patients with minor TBI (GCS 13-15) and a mean age of 44.8±23.8 years were included in the study. The most common mechanism of trauma was falls. Patients with positive CT findings had significantly higher glucose levels than patients with negative CT findings. Using ROC curve analysis, serum glucose levels higher than 120 mg dl-1 were the optimal cutoff value for the detection of patients with positive CT findings with a sensitivity of 74.4% and a specificity of 90.7%. Serum glucose level evaluation at presentation in the emergency department may aid CT decision-making in mild TBI
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Observational and Genetic Associations of Resting Heart Rate With Aortic Valve Calcium
It is unknown if lifelong exposure to increased hemodynamic stress from an elevated resting heart rate (HR) may contribute to aortic valve calcium (AVC). We performed multivariate regression analyses using data from 1,266 Framingham Heart Study (FHS) Offspring cohort participants and 6,764 Multi-Ethnic Study of Atherosclerosis (MESA) participants. We constructed a genetic risk score (GRS) for HR using summary-level data in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) AVC Consortium to investigate if there was evidence in favor of a causal relation. AVC was present in 39% of FHS Offspring cohort participants and in 13% of MESA cohort participants. In multivariate adjusted models, participants in the highest resting HR quartiles had significantly greater prevalence of AVC, with a prevalence ratio of 1.19 (95% confidence interval [CI] 0.99 to 1.44) for the FHS Offspring cohort and 1.32 (95% CI 1.12 to 1.63) for the MESA cohort, compared with those in the lowest quartile. There was a similar increase in the prevalence of AVC per standard deviation increase in resting HR in both FHS Offspring (prevalence ratio 1.08, 95% CI 1.01 to 1.15) and MESA (1.10, 95% CI 1.03 to 1.17). In contrast with these observational findings, a HR associated GRS was not significantly associated with AVC. Although our observational analysis indicates that a higher resting HR is associated with AVC, our genetic results do not support a causal relation. Unmeasured environmental and/or lifestyle factors associated with both increased resting HR and AVC that are not fully explained by covariates in our observational models may account for the association between resting HR and AVC