1,202 research outputs found
Assessment of the performance of the Chilbolton 3-GHz Advanced Meteorological radar for cloud-top height retrieval
The Chilbolton 3-GHz Advanced Meteorological Radar (CAMRa), which is mounted on a
fully steerable 25 metre dish, can provide three-dimensional information on the presence of
hydrometeors. We investigate the potential for this radar to make useful measurements of
low-altitude liquid water cloud structure. In order to assess the cloud-height assignment
capabilities of the 3-GHz radar, low-level cloud-top heights were retrieved from CAMRa
measurements made between May and July 2003 and compared with cloud-top heights
retrieved from a vertically pointing 94-GHz radar that operates alongside CAMRa. The
average difference between 94-GHz and 3-GHz radar derived cloud-top heights is shown to
be -0.1±0.4 km. In order to assess the capability of 3-GHz radar scans to be used for
satellite-derived cloud-top height validation, Multi-angle Imaging SpectroRadiometer
(MISR) cloud-top heights were compared with both 94-GHz and 3-GHz radar retrievals. The
average difference between 94-GHz radar and MISR cloud-top heights is shown to be
0.1±0.3 km while the 3-GHz radar and MISR average cloud-top height difference is shown
to be –0.2±0.6 km. In assessing the value of the CAMRa measurements, the problems
associated with low reflectivity values from stratiform liquid water clouds, ground clutter,
and Bragg scattering resulting from turbulent mixing are all addressed. We show that in
spite of the difficulties, the potential exists for CAMRa measurements to contribute
significantly to liquid water cloud-top height retrievals leading to the production of twodimensional
transects (i.e. maps) of cloud-top height
Enabling strain imaging in realistic Eulerian ultrasound simulation methods
Cardiovascular strain imaging is continually improving due to ongoing advances in ultrasound acquisition and data processing techniques. The phantoms used for validation of new methods are often burdensome to make and lack flexibility to vary mechanical and acoustic properties. Simulations of US imaging provide an alternative with the required flexibility and ground truth strain data. However, the current Lagrangian US strain imaging models cannot simulate heterogeneous speed of sound distributions and higher-order scattering, which limits the realism of the simulations. More realistic Eulerian modelling techniques exist but have so far not been used for strain imaging. In this research, a novel sampling scheme was developed based on a band-limited interpolation of the medium, which enables accurate strain simulation in Eulerian methods. The scheme was validated in k-Wave using various numerical phantoms and by a comparison with Field II. The method allows for simulations with a large range in strain values and was accurate with errors smaller than −60 dB. Furthermore, an excellent agreement with the Fourier theory of US scattering was found. The ability to perform simulations with heterogeneous speed of sound distributions was demonstrated using a pulsating artery model. The developed sampling scheme contributes to more realistic strain imaging simulations, in which the effect of heterogenous acoustic properties can be taken into account
Hospital revascularisation capability and quality of care after an acute coronary syndrome in Switzerland.
BACKGROUND: Patients with acute coronary syndrome (ACS) transferred to regional nonacademic hospitals after percutaneous coronary intervention (PCI) may receive fewer preventive interventions than patients who remain in university hospitals. We aimed at comparing hospitals with and without PCI facilities regarding guidelines-recommended secondary prevention interventions after an ACS.
METHODS: We studied patients with ACS admitted to a university hospital with PCI facilities in Switzerland, and either transferred within 48 hours to regional nonacademic hospitals without PCI facilities or directly discharged from the university hospital. We measured prescription rates of evidence-based recommended therapies after ACS including reasons for nonprescription of aspirin, statins, β-blockers, angiotensin converting-enzyme inhibitors (ACEI) / angiotensin II receptor blockers (ARB), along with cardiac rehabilitation attendance and delivery of a smoking cessation intervention.
RESULTS: Overall, 720 patients with ACS were enrolled; 541 (75.1%) were discharged from the hospital with PCI facilities, 179 (24.9%) were transferred to hospitals without PCI facilities. Concomitant prescription of aspirin, β-blockers, ACEI/ARB and statins at discharge was similar in hospitals with and without PCI facilities, reaching 83.9% and 85.5%, respectively (p = 0.62). Attendance at cardiac rehabilitation reached 55.5% for the hospital with PCI facilities and 65.7% for hospitals without PCI facilities (p = 0.02). In-hospital smoking cessation interventions were delivered to 70.8% patients exclusively at the hospital with PCI facilities.
CONCLUSION: Quality of care for patients with ACS discharged from hospitals without PCI facilities was similar to that of patients directly discharged from the hospital with PCI facilities, except for in-hospital smoking cessation counselling and cardiac rehabilitation attendance
A bacterial-based algorithm to simulate complex adaptive systems
Following a bacterial-based modeling approach, we want to model and analyze the impact of both decentralization and heterogeneity on group behavior and collective learning. Inspired by bacterial conjugation, we have defined an artificial society in which agents' strategies adapt to changes in resources location, allowing migration and survival in a dynamic sugarscape-like scenario. To study the impact of these variables we have simulated a scenario in which resources are limited and localized. We also have defined three constraints in genetic information processing (inhibition of plasmid conjugation, inhibition of plasmid reproduction and inhibition of plasmid mutation). Our results affirmed the hypothesis that efficiency of group adaptation to dynamic environments is better when societies are varied and distributed than when they are homogeneous and centralized
Characterization of the Muscles within the Beef Forequarter
Thirty - four muscles/muscle groups, each greater than .1 kg, were dissected from 16 forequarters to establish a data base of individual muscle yields, palatability profiles and chemical composition. Carcass data from the 16 steers revealed the following averages: carcass weight - 288.4 kg, yield grade - 3.2, and quality grade – low choice. Individual muscle yields, tenderness profiles and chemical analyses indicated that the muscles within the forequarter are extremely variable. However, several of the larger muscles within the forequarter possess tenderness profiles comparable to the longissimus dorsi, the major muscle within rib steaks. This study suggests that maximum utilization of the beef forequarter may best be achieved when individual muscles are fabricated and marketed according to their size and tenderness potential
The importance of insect sperm : sperm ultrastructure of Hermetia illucens (black soldier fly)
Sperm structure and ultrastructure of Hermetia illucens was determined by light microscopy and transmission electron microscopy. The main sperm components were similar as for other Dipteran subspecies, while the ultrastructure revealed distinguishing features in the zone of overlap and anterior flagellar region. Sperm varied in size indicating sperm polymorphism. The head region is lacking an acrosome. The zone of overlap consisted of uniquely organized centriolar adjunct material, partly forming electron dense areas to finally form an outer ring separating the mitochondrial derivatives from the 9 + 9 + 2 axoneme. Accessory bodies arising from the zone of overlap are flanked by smaller to large mitochondrial derivatives into the anterior flagellum. This study confirms sperm structure diversity between brachyceran subspecies and support its relationship with nematoceran subspecies.The Faculty of Natural Science, University of the Western Cape.http://www.elsevier.com/locate/tice2020-08-01hj2019Anatomy and Physiolog
Time-dependent diagnostic performance of a rapid troponin T version 2 bedside test in patients with acute coronary syndromes
New insights into the pathogenesis and nonsurgical management of Graves orbitopathy
Graves orbitopathy, also known as thyroid eye disease or thyroid-associated orbitopathy, is visually disabling, cosmetically disfiguring and has a substantial negative impact on a patient’s quality of life. There is increasing awareness of the need for early diagnosis and rapid specialist input from endocrinologists and ophthalmologists. Glucocorticoids are the mainstay of treatment; however, recurrence occurs frequently once these are withdrawn. Furthermore, in >60% of cases, normal orbital anatomy is not restored, and skilled rehabilitative surgery is required. Clinical trials have shown that considerable benefit can be derived from the addition of antiproliferative agents (such as mycophenolate or azathioprine) in preventing deterioration after steroid cessation. In addition, targeted biologic therapies have shown promise, including teprotumumab, which reduces proptosis, rituximab (anti-CD20), which reduces inflammation, and tocilizumab, which potentially benefits both of these parameters. Other strategies such as orbital radiotherapy have had their widespread role in combination therapy called into question. The pathophysiology of Graves orbitopathy has also been revised with identification of new potential therapeutic targets. In this Review we provide an up-to-date overview of the field, outline the optimal management of Graves orbitopathy and summarize the research developments in this area to highlight future research questions and direct future clinical trials
Diabetes and baseline glucose are associated with inflammation, left ventricular function and short- and long-term outcome in acute coronary syndromes: role of the novel biomarker Cyr 61.
Hyperglycemia in the setting of an acute coronary syndrome (ACS) impacts short term outcomes, but little is known about longer term effects. We therefore designed this study to firstly determine the association between hyperglycemia and short term and longer term outcomes in patients presenting with ACS and secondly evaluate the prognostic role of diabetes, body mass index (BMI) and the novel biomarker Cyr61 on outcomes.
The prospective Special Program University Medicine-Acute Coronary Syndrome (SPUM-ACS) cohort enrolled 2168 patients with ACS between December 2009 and October 2012, of which 2034 underwent PCI (93.8%). Patients were followed up for 12 months. Events were independently adjudicated by three experienced cardiologists. Participants were recruited from four tertiary hospitals in Switzerland: Zurich, Geneva, Lausanne and Bern. Participants presenting with acute coronary syndromes and who underwent coronary angiography were included in the analysis. Patients were grouped according to history of diabetes (or HbA1c greater than 6%), baseline blood sugar level (BSL; < 6, 6-11.1 and > 11.1 mmol/L) and body mass index (BMI). The primary outcome was major adverse cardiac events (MACE) which was a composite of myocardial infarction, stroke and all-cause death. Secondary outcomes included the individual components of the primary endpoint, revascularisations, bleeding events (BARC classification) and cerebrovascular events (ischaemic or haemorrhagic stroke or TIA).
Patients with hyperglycemia, i.e. BSL ≥ 11.1 mmol/L, had higher levels of C-reactive protein (CRP), white blood cell count (WBC), creatinine kinase (CK), higher heart rates and lower left ventricular ejection fraction (LVEF) and increased N-terminal pro-brain natriuretic peptide. At 30 days and 12 months, those with BSL ≥ 11.1 mmol/L had more MACE and death compared to those with BSL < 6.0 mmol/L or 6.0-11.1 mmol/L (HR-ratio 4.78 and 6.6; p < 0.001). The novel biomarker Cyr61 strongly associated with high BSL and STEMI and was independently associated with 1 year outcomes (HR 2.22; 95% CI 1.33-3.72; Tertile 3 vs. Tertile 1).
In this large, prospective, independently adjudicated cohort of in all comers ACS patients undergoing PCI, both a history of diabetes and elevated entry glucose was associated with inflammation and increased risk of MACE both at short and long-term. The mediators might involve increased sympathetic activation, inflammation and ischemia as reflected by elevated Cyr61 levels leading to larger levels of troponin and lower LVEF. Trial registration Clinical Trial Registration Number: NCT01000701. Registered October 23, 2009
Role of hyaluronan in human adipogenesis : evidence from in-vitro and in-vivo studies
Hyaluronan (HA), an extra-cellular matrix glycosaminoglycan, may play a role in mesenchymal stem cell differentiation to fat but results using murine models and cell lines are conflicting. Our previous data, illustrating decreased HA production during human adipogenesis, suggested an inhibitory role. We have investigated the role of HA in adipogenesis and fat accumulation using human primary subcutaneous preadipocyte/fibroblasts (PFs, n = 12) and subjects of varying body mass index (BMI). The impact of HA on peroxisome proliferator-activated receptor gamma (PPARγ) expression was analysed following siRNA knockdown or HA synthase (HAS)1 and HAS2 overexpression. PFs were cultured in complete or adipogenic medium (ADM) with/without 4-methylumbelliferone (4-MU = HA synthesis inhibitor). Adipogenesis was evaluated using oil red O (ORO), counting adipogenic foci, and measurement of a terminal differentiation marker. Modulating HA production by HAS2 knockdown or overexpression increased (16%, p < 0.04) or decreased (30%, p = 0.01) PPARγ transcripts respectively. The inhibition of HA by 4-MU significantly enhanced ADM-induced adipogenesis with 1.52 ± 0.18- (ORO), 4.09 ± 0.63- (foci) and 2.6 ± 0.21-(marker)-fold increases compared with the controls, also increased PPARγ protein expression (40%, (p < 0.04)). In human subjects, circulating HA correlated negatively with BMI and triglycerides (r = −0.396 (p = 0.002), r = −0.269 (p = 0.038), respectively), confirming an inhibitory role of HA in human adipogenesis. Thus, enhancing HA action may provide a therapeutic target in obesity
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